The reason he gave was that it is not as accurate to "punch" as T-style as it is to "punch" the standard style of release. T-grip releases are for back-tension triggering. Since "punching" the trigger is often necessary in hunting, he said to steer away from T-grip style releases.
To tell you the truth I don't know what he is talking about. Punching the trigger is necessary in hunting???? IMO punching should be avoided completely in any situation. It will effect accuracy. T-grips are for back-tension triggering????? There are hand helds that are made exclusively to be trigger only by back tension, but I would not use them for hunting. You can also fire most finger style releases with back tension.
I use a tru-ball King George, which is triggered by the thumb, and/or pinky. The release basically has no travel and is mainly activated by pressure. I love the release and have used it for hunting. Only problem is its noisy. For hunting I use a pro-diamond. It does have travel, but is completely silent. Currently I am using a talon head with a string loop on the string. But I also have a double which is interchangable.