In fact, it is false to think that Gavin or anybody else has any authority to hard fork Bitcoin.  There is no such authority; Bitcoin was designed as a system where authority counts for nothing.  The only thing that counts is mining power.

All Gavin can do -- in fact, all that anyone can do unless they are a miner -- is put the code for a hard fork into a client.  

Nobody forces a miner to run that version of the code.  Miners have been tweaking code and compiling their own clients forever.  

The fact is that the only people who get a vote in whether or not a hard fork actually happens are the miners.  And their vote is by hashing power.  

Forget Gavin or anybody else.  What it comes down to is whether the miners choose to put that version number into the header of the blocks they mine, or not.  If they don't, there is no fork.  If they decide they want a different fork and hire some random coder we've never heard of to write it, then if they make a 95% decision, they can deploy that fork without consulting us or even warning us.  

This fork issue is the decision of the miners.  Nobody else, anywhere.