I'm not sure, but I guess that it would help if you disable bounce-bans it won't take off any bans set by server, otherwise all bans set by server after the netsplit will be taken off, no matter if it matches an +o user, if it matched +o user in your case, it must have been a coincidence
Settings you might like to change in conf, set
bounce-bans 0 and set
bounce-modes 0 makes bot ignore all modes set by server.
set bounce-modes 1 makes bot take off bans and any other modes set by server, set
bounce-bans 1 will take off only bans but will leave the other modes set by server
# Set this to 1 if you want to bounce all server bans.
set bounce-bans 0
# Set this to 1 if you want to bounce all server modes.
set bounce-modes 0
Hope it helps