Intentional Foul on Try

[Grail]

Question to the masses:

In a game the other night, the Center on the Red team kept grabbing the opposing team's Center's jersey. He only did it when the were jockeying for position, and it never resulted in the jersey being extended away from the body. He simply would lay his hand on the players back and make a fist with the jersey in hand.

When I saw an advantage take place I called the hold (common foul), administered the penalty and went on. The question is, is this intentional. By Webster it is clearly intentional, and I've seen it called that way. I thought making that call would open a can of worms I preferred to to deal with and didn't make the call. I discussed it with my parntner at half-time and he agreed with me. However, in looking back on the game I can't help but think I should have called it the first time I saw it and ended it right there.

Any thoughts?