The start of a hand?

[RJT]

I had been under the impression that once the dealer starts to shuffle, the hand has started. In another post, a poster said I was in error.

1) Is he right?
2) If that is the case, then if a player asks for a deck change during a shuffle, there is no reason for the dealer not to do so immediately. Bummer.

I am asking about cash games not tourney rules.