Let's see:
* there's a list of 6000 people to be arrested, military and non-military, which must have existed before
* offensive on the ground took place at a time when they must have known Erdogan wasn't there
* they could have shot down his plane with F16s, but didn't
* the coup was generally terribly organized, in a country where the military certainly knows how to do it
* Erdogan is known to be a mischievous POS
Many people are sceptical and for good reasons.