'Maybe this was deliberate on the mayfly's part and the mastermind wanted sherlock and watson at the barracks for some reason?'
'they wouldnt have even taken on the guardsman case without mary playing her little thumbs up games'
Good points, giraffes!
And the more I read/think, the more I think the pregnancy 'revelation' and Mary's reaction to it were very suss indeed.
On a completely different note, I've left loads of weddings early and I'm neither a murderer nor a busy consulting detective. I must just be just ultra-antisocial 