As a TD, that’s totally your discretion. I think it also depends on the context of the event too. While I was reading this I wasn’t like “WHAT COACHING NEW PLAYERS, BUT YOU CANT!”. At smaller events and gatherings where there isn’t a whole lot on the line, there’s much more room for leniency when it comes to coaching. There’s probably an argument for coaching in certain circumstances!
During my first ever league night when I was still involved with the Pittsburgh league, people were super helpful, even when it was my turn. Of course they were helpful with each other too. But it was the fact that they were willing to help me which was one of the main reasons I kept going back; the people were incredibly nice and wanted to see me improve. There’s certainly a place for that kind of thing, especially with newer, less experienced players. I applaud you for that for sure!
Like you said, If you’re whipping out your phone to watch Bowen, that needs to be done when you’re waiting for your next ball, or before you get to the event. I don’t know what I’d do if I saw that at a tournament!