There are times when players chat and forget the clock is running down, particularly when it's a fun game. There are many other reasons why someone may time out too.
But the OP's post is about the freeze that occurs in an alt shot when the timer gets to zero. The only way to get going again is for someone to disconnect, which is far from ideal. This has been the subject of a number of threads and only started since the last update. Hopefully WGT know about it and will fix it soon.