This is looking more and more like it was a 'fake' coup for Erdogan to seize even more power.
The army could have arrested him, but chose to coup when he left to vacation inside Turkey? By the way, he's never "vacationed". Ever. The surrendering soldiers said they were told it was a routine drill until the call came that it would be a coup. Soldiers said they were totally unprepared and had no plan except hold bridges. Those poor kids looked confused as fuck when they surrendered.
At the very least, Erdogan had plenty of advance knowledge but let this go ahead so he could capitalise on it.