Yeah pretty sure I've seen higher, can't remember the exact amount.
But logically 10 can't be the record, simply look at my games this season, anyone's games, and you'll see about 7 3 pointers made quite regularly. I just don't see how it would be possible for 10 to be the record.
Also, a few seasons ago, before changes to the game engine were made, far more points were scored, so I would have to presume that there would have been more than 10 3 point shots made by 1 player then.