Interesting discussion.
Before the match... I found this
6.5.3 A match, tournament or league will be deemed to have started on the first day that competitors (including those specified above) shoot for score and will be deemed to have ended when the results have been declared final by the Match Director
I agree, its when shooters arrive and are on the match berms. They could be on berms outside the match and then they would fall under the range rules.
So OP's statement that it happened before the match started is not correct. Shooter was on a match bay. So assuming this was a Level 1 match and as long as the shooter didn't point in a unsafe direction on the berm, I can't point to an "explicit" rule violation.