I really think that the time/place systems they use nowadays contribute to the more-frequent "collapses" after the finish.
BITD (and still, at most meets) you had to travel through the chute--you had to *keep moving* after the finish. With no-chute races, people tend to stop dead, which is just about the best way to make people wobbly and encourage them to go down.
I can still remember Prefontaine, after his first NCAA xc win, being dragged through the chute by the officials. He was pretty much spent, but being forced to move through the chute probably helped him recover faster.