Question about "only goalkeepers" at higher ranks

I know a lot of people at lower ranks just like to hang around in net, but this was a match with Champion 1s and he was a Diamond 3. I was solo queueing normal 3v3 and there was this guy who had a name which indicated he wouldn't leave the net, but I thought he was just joking. He actually stayed in the net the whole game and he left me and our other teammate to attack. We ended up winning 2-1, but multiple times I was confused on what to do since I'm not used to only rotating with 2 people in a 3v3 game. It was incredibly annoying, but I didn't see a reason to report him and just let him do his thing. I don't think he was breaking any rules, but he did inconvenience both our teammate and myself since he forced us to play awkwardly. I would've probably been a lot more salty toward him had we lost. I just wanna know what everyone's attitude would be if they had a teammate like this at higher ranks? Would everyone else be okay with it?