I will say that the bug with the pelican leaving with only one player is actually pretty funny. It can be consistently reproduced by dropping directly onto the pelican with your drop pod, it will insta extract and leave everyone behind.
As soon as you see flames or smoke from the pelican you're fucked. Its atleast so well reproduced that we will routinely drop all samples on one guy, and turn it into ESCORT THE VIP. Makes for some fun not gonna lie.
Could it be a hidden/removed feature where the Pelican can take damage, but leaves instead of being blown up? That also explain why someone mentioned that dropping on top of it also triggers this bug.