Yes absolutely that was the butterfly moment
Here's the thing. Leave would have lost were in not for Boris Johnson. The big question really is was Boris an out-an-out Brexiteer or an opportunist who realised there'd be a leadership battle in 2017/18?
Look at his Brexit credentials first. For such time as he was Mayor of London he's on the record as having made plenty of pro-European speeches and talking points. Let's not forget that it took him a week to make up his mind who to campaign for. Can you seriously imagine the likes of Gove, IDS, Fox et al having to sit down and think which side to support. Any Brexiteers I know has pretty well known which side of the argument they're on years ago.
The calculation as Boris saw it lies in the mechanism that the Tories use to elect their leader. If Remain had won the referendum then George Osborne was going to be the continuity Cameron candidate having presided over the so-called economic recovery and introduction of austerity. Osborne would win the parliamentary party nomination, but needn't be guaranteed to win the final vote amongst the party membership. Conversely Boris faced the opposite problem. He could conceivably win a poll amongst party members but needn't be guaranteed to come through the parliamentary filtering system where he doesn't enjoy anything like the same level of support.
Basically Boris was going to fall about 80 votes short in Westminster so needed to find a constituency within the party who could propel him into second place so that he could beat Theresa May and then take on George Osborne on much more favourable terms. Naturally he figures that is he gallantly campaigns for 'leave' and puts up a good showing in 2016 but narrowly loses, then in 2017/18 he can turn round and hopefully convert that into about 120 - 130 votes when the leadership election starts. Enough for second place
The problem of course is that Boris c0cks the whole thing up and wins. At this point he isn't too concerned however as Cameron resigns and he thinks his chance comes early. He hadn't however reckoned on Gove, who knew what he was about all along, and now that he'd served his purpose and was therefore expendable, Gove duly slipped the knife in
Boris Johnson is now left having to live a lie and adopt a new political position or otherwise face mass ridicule. It's a little bit like the 'Twelfth Night' in places
Now this was hinted at in the Brexit debate, principally by Nicola Sturgeon, but she never took the opportunity in any of the debates to explain it to the British people and expose Johnson for what he was doing by laying out the rules which Johnson was trying to worm his way through. Instead she just relied on a soundbite and trusted the people to put the pieces together
This all stems from Calamity Cameron. If he hadn't been so stupid as to say "on your marks, get ready" then Brexit wouldn't have happened. It was perhaps telling that as he slid his oily way out of Downing Street he was asked what his greatest achievement was after 7 years, and he nominated 'gay marriage'. I suppose it's really a question of what else could he say? The Big Society? (remember that?) Libya? Failing to hit his immigration targets? Failing to hit his environmental targets? Taking us into a double-dip recession? The only thing he didn't do that badly was a passable impression of Julia Gillard