Perhaps move the new game button where the "accept rematch" alternative was?
That would be really annoying.
If I want to play a new game I don't want to inadvertently accept a rematch.
This sort of misclick would be much more common that the attempted decline you describe.
Hi,
the decline rematch button is unfortunately placed exactly where the new game button is.
If you are polite enough to actually click on decline rematch when you do not have time for another game (instead of just ignoring the rematch request), it sometimes happens that the previous opponent withdraws the rematch request just before your click. The accept/decline rematch UI changes, and a 'new 15+10' game button appears in the exact same spot where the decline rematch button was. So you end up clicking on new game, and starting a new game without intending to play.
Perhaps move the new game button where the "accept rematch" alternative was?