Comment by zdragnar

A highly acute dose could kill in seconds, but a lower dose can cause confusion, headaches, dizziness and more prior to inducing a coma and death.

It is not outside the realm of possibility that he became confused and in pain, decided to lie down to sleep it off, then died in his sleep. My own father in law suffered a significant blow to the head and, despite knowing all the signs of a concussion and what to do about them, got up and slept it off- the very last thing one should do. He was simply too confused to do anything else.

His story had a happier ending than Alan's, but it goes to show that the accidental death theory isn't implausible.