But this is not quite it.
Doroshenko had borrowed the same type vest from a friend before the trek. This is a line from the protocol of identification of the items by relatives:
Case file 240 (back)3. Sleeveless fur vest borrowed from Farid Gaynutdinov, course R-463
In the protocol of the items found in the tent Yudin said that the following items belonged to Kolevatov. Note that they were not found on Kolevatov, so Yudin could have been easily mistaken. This could be Doroshenko's vest, and he could have unwillingly contributed to the mess in the case files. Ivanov is not solely to blame.
Case files 168. Identified as Kolevatov's belongings: black backpack.
Blanket of soldier cloth, jackets and pants,
fur vest...
On the other hand Kolevatov's relatives did not identify any such vest, so it must belong to someone else.