OFP player Lucky reported this problem to me:
I've found an additional bug with the Pathfinder mission. If you take out the second Shilka on the edge of Chapoi and save the game or OFP automatically updates your retry position before the choppers start to make their pass, you're in a world of hurt. I have found upon continuing the mission from this save point that the helicopters won't show up. Your squad inevitably gets chewed to pieces by two T80s, a T72, a BMP and about a platoon plus of reserve enemy infantry.
I thought it was a one time bug, but I've replayed the mission from the start two more times and have reproduced the same error. The first time, I manually saved the mission's retry point . The next two time, OFP automatically updated the mission's retry position. If you attempt to load the saved mission from this point, you're done for without those Cobras!
Oh Well! Probably get fixed in a patch!
I've since forwarded this bug report to BIS support. I'll update this item, should I receive a reply.