Namus on the link you have posted and this site by the parent of Peter. As far as them being school mates it is in a video of the missing honor students in a previous page.
According to the Charley Project, none of the Peter McColl sightings after Solano/The Alameda have been confirmed (thus verified). In other media, I believe Peter's mother found the "Montclair theory" you're referring to be
promising, but I'm not sure if that means "verified". Until recently, many also thought the homeless Telegraph Avenue girl was a solid lead until notions were dispelled by the very person in subject.
For all intents and purposes, I feel this reinforces what I explained in my second post about how a lot of unsorted information turned this case into the shaggy dog mystery it isn't. In some respects, it echos the Kristen Modafferi disappearance - both occurred in the Bay Area two years apart while the internet was still in its infancy, both parties were around the same age, and the trail of both individuals ended not far from a point where mother nature is potentially more ruthless/violent than human nature.
For whatever it's worth, this is how I've tied together the Tilden accident theory (based on personal facts about the missing teenager that, so far, have not been argued against):
1.
Crew, which McColl was part of, is one of - if not the most - demanding high school sports on the physical and mental level. Students don't become rowers because "they think it's cool", but because they want to push all boundaries of their endurance. Intensive training is on the mind 24/7, and many high school Crew members become elite college athletes. There's absolutely no leeway for disruption, whether that means associating with people who mean you harm or matters beyond one's control ...
2. McColl was recovering from a
broken arm, which would have inevitably restricted some degree of physical exercise between school terms. Just how much is unknown, but as rowing requires 100% of the body, even having a single hand out of commission would be detrimental. If Peter's mom noted Peter seemed "anxious" before his disappearance, anxiety about losing his spot on the Crew team is not a far-fetched theory as to why.
3.
Tilden Park, a mile up the hills from the McCall residence, was a favorite "draw" of the missing teenager. As far as hazards, it doesn't hold the smallest candle to Kilimanjaro or the Himalayas, but people HAVE died up there, and injuries are not out of the ordinary (not all end up on the news). Landslides and sinkholes have gotten worse over the years, and seemingly bottomless caves and fissures can be observed from the more rugged trails. Add foliage and tree branches on top, and you have a naturally-occurring pitfall.
Again, this is just a theory. I understand it won't be accepted by everyone, and the archived bus/taxi/thrift store sightings will continuously be reiterated and inquired about here. That's fine. On the flip-side, at least there's common ground on wanting this mystery to be solved.
Hope everyone has a good new year and may this case be officially cracked before its three-decade mark.