Yet it is. His wins were negated by her losses, they’re on the same team.
If your thought process is like this I hope that I never have to participate with you in any sort of team event.
It depends on the sort of team event, if its one where people co-operate to get a total outcome I agree with you. But in this sort of event there is no co-operative element as its just people grouped together showing individual performance. So even if he performed the best out of everyone, if his teammate did the worst it would literally cancel out his performance due to the team aspect.