The timing of this is pretty awkward. They just posted an application and now you make the report, how long ago did this incident happen exactly?
Either way in this case I think it's based 2 big factors, the intention and the outcome.
It's obvious this was intentional, black is aware pressing buttons without wardens permission is forbidden and based on how he reacted it's a safe assumption this was intentional. The outcome was less harmful, only 1 person on blue died. But I think at that point there's good enough cause to take action here. This could of turned out far worse with more people then just that one blue dying. Tdlr this is intentional teamkilling, and I think "warning" people for intentional teamkilling of others is far too forgiving.
Just posting this here. Jb admins wanted to talk about it but I'll also leave my thoughts here since this person is an applicant and I don't want my view getting missed!