Corrected entry: It is revealed in this movie that there is an "Escape Clause". However, if you look back on the very first Santa Clause movie it was established that being Santa Claus is a lifetime commitment or in the clause's terms "unable to do so, by either accident or design". Hence, the instruction that his coat must be worn by someone else in case something happens to him so that someone else will always carry on Santa's work. Scott already tried in the first movie to get out of the responsibility but the clause doesn't permit him to do so.
Knever
4th Nov 2007
Correction: That's the whole point of the movie. Of course it doesn't seem like there's a way out, but the Escape Clause is exactly that, an override to the original clause that makes it null.
Knever