Totally understood! But what if someone convinced Dylan to get into a boat and go out on the lake Sunday night after 8:00p to do some late night fishing? If this is something he had done and enjoyed in the past, it might not be hard to convince him to do that. Especially if there was nothing else going on. Dad going to bed early and Dylan watching tv alone on the sofa seems so....abject....given the circumstances of his just having arrived.
The thing that, in my mind, makes this unlikely is the scent the dogs hit on out on open water was cadaver scent, not a living scent. So a sedating drug such as a roofie, followed by ( ugh ugh

I really REALLY don't want to type this) a possible bloodless strangulation, then a trip out onto the lake by cover of darkness......
I hope Dylan's family are not reading here. My heart is with them all, all who are innocent of any harm to Dylan. My heart is also with Dylan, whether he is in heaven or on earth. Come home Dylan. Please come home.