Reddit reviews On the Front Lines: The Experience of War through the Eyes of the Allied Soldiers in World War II

>The next moment or so was a terrifying moment for the crew, for those at least who had not been mangled, decapitated or sliced in two by the shell or flying fragments. Even if a tank was only immobilised by a hit, everyone knew that they only had a very short respite before another shell would come ripping through the hull. Peter Elstob’s crew soon learnt an important lesson of tank warfare, that ‘when a tank was hit by an armour-piercing shell those who were still alive and able to move got out fast before the next one hit; the whole thing was as unlike a boxing match as it could be, because in tank battle the first hit was the winning one’. The first or second hit was almost certain to set the tank on fire and it was then that any watching infantry were truly thankful that they had never been assigned to an armoured unit.

http://www.amazon.com/On-Front-Lines-Experience-Soldiers/dp/0471551481?tag=viglink20265-20

Though I concede that it does mention being "immobilized", but then goes on to say any hit from a AP round.
From what I've read/seen after an initial hit the crew almost always immediately bails, but obviously not in every case. Of course in the case of a ricochet the crew probably won't bail, but in terms of WT we're talking about a pen that kills some of the crew, not none damaging ricochet.