Won't do much of anything.
Grip size is about comfort. Doesn't really affect "the release" at all. In fact, if anything, a fatter grip may lead to you having to roll the hands a bit more if the grip gets up into your palm.
It’s interesting that a fellow competitor won’t help. I’m pretty sure we all help someone in our group look for an errant ball.
But here they are trying to Monday Qualify. Perhaps they were tied or 1 up or down and dear old dad decided it would be in his sons best interest not to help. Who knows, pure conjecture on my part.
How do you handle assisting a fellow player? I have to say hitting my 2nd shot before assisting another player is my priority to keep my place of play going for the round. I’m more than happy to assist after that.
The only time I deviate from that is when they didn’t see where it went but I had a line on it. Did that several times today as a guest had poor eye site. It actually helped pace of play.