Thanks for the correction. I still wonder whether there were any minors present and where the responsible adults were.
At any official skating event, there may be official parties. But many more parties are not official. Therefore there are no "responsible adults". At important comps, the word goes around "Party in X's room!" and it goes from there. (And yes, this is very much like what happens in many High Schools and colleges.)
Locally, and because it's local, these parties take place at people's homes where it's much easier to slip away unnoticed and there are still no "responsible adults" because the party is being put on by other skaters who may be legally adults but barely. Because there is a range of ages training together, there are minors there as well as adults.
Is it not mandatory yet for US coaches to undergo a background check?
Anyone can be a coach. If a coach wants to belong to the PSA/USFS, there are some criteria but plenty of people coach outside any system. Rinks might require PSA/USFS/ISI membership but mostly they only care that the coach has insurance. And they also sometimes turn a blind eye to any unofficial coaching going on.
For example, there was a situation when I was still skating where a guy -- a former skater from Russia who wasn't particularly well-known -- who was coaching a young lady. He was not an official coach -- no credentials, no insurance, nothing official -- but he was definitely coaching a few students. On top of that, we were pretty sure they were sleeping together even though he was in his 30s and she was in HS.
And there was really nothing we could do about it. Her parents knew she was being "coached" by this mini-Morozov but all they could see was "Russian coach" and were sure he would take their daughter to the top.
So do US coaches undergo background checks? Define "US coaches." Because this dude was coaching in the US but USFS had no idea who he was.