I am thinking the same thing trail mix is, you have no way of knowing if he was actually clean and sober, you were not present 24/7. So maybe he talked and texted with you daily, and then ended his evening drunk or stoned? Doesn’t take very long self medicate with drugs or alcohol...
As far as “ he planned this” I don’t know about that, perhaps you just got a front row seat to who he really is today...