ADMIN NOTE:
Hey everyone,
At this point, nobody knows what has happened to Philip, whether accident, misadventure, or foul play, etc ... and there is certainly no officially named POI or suspect in Philip's disappearance.
Please read The Rules (linked in my signature). Websleuths is Victim Friendly, and victims include loved ones and friends of a missing person. It's fine to ask questions respectfully or post an opinion, but do so without casting aspersions or making direct or indirect accustions at anyone, let alone at a friend who is trying to help find one of his running buddies.
Post respectfully and responsibly, in accordance with Websleuths rules, or your post will be removed and there may be a temporary or permanent loss of posting privileges.
The thread will reopen once we've had a chance to clean it up.