Extra time for warm-ups?
 

Again, this occurred at AAU Nationals. So for warm-ups, we have 2 minutes of shared time on the court, then each team gets 4 minutes to use the whole court.

During the 4-minutes for one of the teams, I noticed that the antennas were both off-vertical. So I went to one antenna to fix it. While I'm fixing it, the coach tells his girls to stop hitting. It takes me 20-30 seconds to fix the antenna. Girls resume hitting, and coach asks for extra time since they had to stop for me. It took me by surprise, honestly. I denied the request, since I didn't think that they needed to stop for me. This really bugged him for the whole match.

I actually then did the same thing for the other antenna while the other team was hitting, and there was no issue at all.

Should I have given his team an extra 30 seconds to hit? What's an extra 30 seconds, right? But at the time, it just felt like I didn't make you stop, so why should I should delay the match?

The more I think about it, the more I think I was wrong. Looking for thoughts.

Wait to fix the antennas?

As Bob said, you and your partner could have fixed them after warmups. If you aren't going to fix them before the coin toss, you can just wait. Their warmups aren't being negatively impacted by a wonky antenna.

That said, since you were on the court doing maintenance, and the team clearly stopped, it wouldn't have killed you to give extra time to make up for the time you were on the court, regardless of whether you intended/needed for them to stop.

Just my thoughts.

But then we're holding up the start of the match. These tournaments are always huge on "time management". The two minutes of shared time is supposed to start as soon as the last match ends. We don't wait for (almost) anything. At the time, I just thought I was keeping things moving.

The antennas should be checked before the start of each match -- even after you fixed them, the teams hit into the net / antennas and they could have moved again. Do it while the teams are shaking hands or while R2 is checking the lineups.