I don't think Tom, or that matter anyone needs to forgo working on changes at any time. The only effect missing a commitfest deadline means is that other reviewers don't offer any promises to give any feedback on it before this round of the commitfest is done.
We don't have a policy of requiring code reviews before changes are committed -- it's up to the commuters judgement whether the patch is type for committing. There has been the suggestion that commiters should concentrate on reviews rather than fresh development during commitfests but nobody is going to do 100% reviewing work for the whole time and nobody could seriously suggest Tom hasn't pulled his weight reviewing patches.
