Your evidence in this case is weak. cytpoway121 posted that BSC address only once, after irsykes in the same bounty thread. It's probably just a dumb mistake after cytpoway121 used someone else's post as a template but forgot to change his own BSC address. He edited the post shortly afterward, though. Shit like this happens, and it doesn't necessarily mean they're using alt accounts, unless there is some additional supporting evidence.