-
Not if you think about it in these terms:
1) David Cameron flounces into EU meetings swinging his schlong around saying (as he supposedly did): "I'm going to win this referendum with a 70% vote so don't you worry your pretty little heads..."
2) The bad thing happens and 'Leave' wins. That is (mostly) a bit of a shock, and as people quickly realise the potential for huge long-term disruption/loss, there is a window of opportunity to make some possibly significant concessions to avoid a whole load of collateral damage. In this instance, we're not talking about Merkel as the decision-maker, but rather as the most influential person at the table, so someone who can win others round.
3) As that window of opportunity closes, the hard brinksmanship of the negotiation process resumes, and everyone tightens their public position.
Every utterance from Merkel has been "no access to the single-market without freedom of movement". I find the idea that she would then do a secret deal, behind the back of the rest of the EU, with the UK, pretty far fetched.