Ballistic Nuclear Submarine Conundrum

Were it not for the inherent seriousness of the incident, this whole event would be laughable. The sort of thing you expect in some lampoon show on television...complete with fake foreign accents. It's reported as a brief contact at slow speed but it is going to cost 50 million pounds to repair both submarines. Some brief contact. The damage seems to have been considerable even though no one is reported injured and the nuclear warheads were not compromised. Seriously, folks. These submarines are undetectable because of ANTI sonar equipment.Then there is the clap trap about this being a rare and unlikely occurrence. So why are submarines designed to evade detection surprised they are bumping into each other? With nuclear weapons and nuclear reactors on board I should have expected a bit more vigilance and then some technology to let them know there is a great big, fat nuclear submarine in front of them. It's daft. Deadly serious but completely daft.