If Iranian sailors "accidentally" sailed into British waters, there'd be hell to pay. But they would be several thousand miles off course, so the accident excuse probably wouldn't wash.
Mullahs are keeping me laughing recently. The Iranian foreign minstry says that they do have a written apology from uk but is not the norm in diplomacy to publish it. Such comment is quite laughable from a rejim that is proud of "tv confession"s it made from UK soldiers.
The only reason Iran looks good is by juxtaposition of the British troops' treatment with that of prisoners held in American captivity--even if all the accusations of blindfolding and gun cocking are true.