Been an RO for a few years and have had to DQ strangers, friends, and family alike. I say don't go with your gut, but go with the rule book. Safety violations, failure to do right, attempt to cheat...it doesn't matter, the end result has to be the same for everyone. I've seen a few other RO's let things go for new shooters while I was directing a match at my local club, I had to explain that failing to call them out not only does them no good since they don't understand the severity of their mistake, but also puts all other shooters in jeopardy.
I'd rather DQ somebody and than allow a dangerous environment.