It is unconfirmed, but there are PSU pilots that have claimed to shoot down Russian jets, although it's unclear what kind of jets specifically.
is one of those pilots, flying Su-27. It is not totally implausible, as there PSU Su-27s and MiG-29s have been fighting with their VKS counterparts (and losing most of the time, as the latter has Su-35s). This guy probably shot down some easy targets like Su-25s, which would make his claim
technically true
.
Though his claim that VKS pilots are afraid of flying due to some sporadic resistance from PSU is not based in reality; the real threat to VKS are