Teamwork?

So I wonder where's the teamwork?
I went to take down a weak opponent's gym and while fighting, someone joined me (Not a spoofer at least, I have seen that person). We were two Gary's against a single poor Rhydon, so it was a quick fight.
But then, the other trainer was faster to place a mon, so that a poor quiet, lonely gym didn't let me ass mine, claiming it is under attack for another 10 minutes.
I must be missing something, cause ... there goes teamwork!
We used to take gyms as a family, placing 4 of us after a joint fight. Nowadays, we'd have to wait 10 minutes and time it well so no spoofer can jump in on 10 minute mark.