VII. What Are the Odds That Jesus Was Speared?
Though he must have had at least a 33% chance of not having died on the cross, John records a spear wound. It has been said that the description of the wound pouring out blood and water (19:34) suggests a mortal wound, being a blow near the heart (McDowell, citing James Thompson, E.H. Day, and William Stroud: 1st ed., p. 198, § 10.4A.1B.1C; 2nd ed., pp. 223-5, § 9.6A.1B.1C). Of course, this is probably an invention--there was a belief that the messiah came "with water and blood" (1 John 5:6-8), representing baptism and death. Consequently, several church fathers (Ambrose, Augustin, and Chrysostom in particular) understood this spearing passage symbolically, not literally: the blood represented the eucharist; the water, baptism. Perhaps also this referred to the Jewish tradition of the time that the rock in the wilderness that Moses smote twice "poured out blood at the first stroke, and water at the second" (Shemoth Rabba, folio 122), the sign of God's grace and the gift of life (and Christ was understood by Paul as representing this rock: 1 Cor. 10:4). Moreover, John is alone in having Jesus perform a transmutation of water to wine (at Cana, 2:1ff.), and this is unlikely to be coincidence. The same symbolism is no doubt intended there. Thus, the wound thus testified to the fact that this was the messiah, and it could therefore be an invention for that purpose. John himself already reports a scriptural reason to invent the spearing (19:37), and makes suspiciously excessive assertions of its truth (19:35).
But even supposing this wound to be genuine, anyone who knows anything about anatomy will agree that the only place in the body where a noticeable amount of water or any clear liquid would ever be visible, along with blood, to a medically ignorant soldier a spear's length away, is the large intestine (and even then only abnormally, e.g. diarrhea), suggesting a wound that is unlikely to be fatal until many days later. I conclude this after consulting several real doctors, contrary to McDowell's citation of Michael Green (1st ed., p. 199, § 10.4A.1B.1C; 2nd ed., p. 225, § 9.6A.1B.1C), since we do not know that the blood did not spurt (the description is too brief and vague for such claims), and blood pouring from a vein does not spurt in any case--only that from an artery does. Moreover, the effect of a flow of distinctly separated serum and clotted blood, visible to a distant layman, is exceedingly unlikely. Unabsorbed water from the large intestine is far more likely in such a case, and even that would only occur if Jesus were suffering from some sort of medical condition that would cause an abnormal accumulation of water there. One might imagine a blow to a full bladder as having the same visible effect, but there are two reasons to discount this: struck from below, the bladder is well-guarded behind one of the thickest bones in the human body and thus is unlikely even to be targeted by a soldier, much less actually pierced from that angle, and it is inconceivable that a man who endured hours of beatings and crucifixion would be able to hold his water throughout.
Munro and Assaf and those other amazing survivals mentioned earlier (Section V) probably occur, let's say, no more than 1 in 1000 times, but a spear wound to the large intestine, though likely to kill in time, is nothing compared to the wounds these people temporarily survived. I must say the odds of surviving such a wound for up to a week must be at least 10%. Throw in the chances of surviving a partial day of crucifixion (33%), and we get a chance of survival, with the spear wound, of 0.33 x 0.10 = 3.3%. With misdiagnosis as well, we get a final chance of 0.00599 x 0.033 = 0.00019767 (roughly 1 in 5000).
But the account of his being speared is illogical and late. It appears only in John, the last of the gospels to be written (after 90 AD). There, soldiers decide not to break his legs because he is dead, and then spear him to make sure he is dead. This is contradictory and inexplicable behavior. The spear wound later comes up in the context of the doubting Thomas story, which also only appears in John. As a late insertion in the story, it looks an awful lot like a rhetorical "vicarious conversion" aimed at answering arguments of skeptics, and being late this is to be expected: such doubts had certainly been voiced by then, and John would have liked to answer them (see also Main Argument). Thus John has as much a motive to invent the spear wound as he has to invent the entire Thomas story, which, after all, is found in no other account, not even in the writings of Paul. All three facts create great doubt that Jesus was stabbed with a spear. This makes survival even more likely. The odds that the spear story is false, based on the fact that three earlier accounts fail to mention it, that John has several rhetorical reasons to invent it, and the account of it does not make sense, I think must be at least 75%. This gives us a 75% chance that the odds of survival and misdiagnosis are 0.0019767 and a 25% chance that they are 0.00019767, for a combined chance of (0.75 x 0.0019767) + (0.25 x 0.00019767) = 0.0015319425 (0.15%).
One might argue that the "not breaking his legs" account must be dropped if we drop the spearing account. In fact, some argue that John felt the need to claim that Christ's bones were not broken in support of prophecy, as is stated explicitly in John 19:36, and many commentators find a connection with the passover-prohibition on bone-breaking, based on Exodus 12.46 and Numbers 9.12, and John's other predilections for such an analogy. Of course, the same passover rule also prohibits taking the flesh outside the house, which doesn't fit here, and John's words are also taken directly from Psalm 34:20, a passage which discusses righteous men in general, and has no overt connection with the messiah or crucifixion or anyone's death. Still, John alone has Jesus buried in the same place he is crucified (19:41), which could be meant as fulfilling the prophecy that the bones never left their house. So there are good reasons for John to invent the whole leg-breaking story to justify his passover lamb analogy (maybe even drawing on a real practice: see Note 3). But even if John invented the story of the leg-breaking, we are still left with no reason to think Jesus' legs were broken, and if the leg-breaking story is true, John still tells us Jesus' legs weren't broken, and no other gospel claims otherwise.
The spearing also has a scriptural reason to be invented or mentioned. Since it is taken from an actual messianic passage in Zechariah 12, it could reasonably be expected to be about the messiah and thus anyone in John's position might assume it ought to apply to Jesus, or they would want it to apply, to "prove" Jesus was the messiah. But that passage also mentions other things, like the blinding of the world's horses, and the besieging of Jerusalem at the same time as the coming of the messiah, which John omits. Thus, he is borrowing only what he wants to use. Our question is thus "why?" The use of the wound to have the symbolism of blood and water and to dramatize the Doubting Thomas story give the most obvious reasons, as I note above. It is also possible that in this or even also the leg-breaking account John may have needed a scriptural passage to justify what really happened. But this is less likely given: (1) the illogic of spearing him after leaving his legs alone, (2) the fact that it dovetails with the already-suspicious Doubting Thomas story and allows the symbolic introduction of blood and water, and (3) it is not mentioned by anyone else, including the three earlier evangelists.
So the conclusion stands so far that the odds of survival and misdiagnosis are (0.75 x 0.0019767) + (0.25 x 0.00019767) = 0.001532 (0.15%).