You were doing 22 mph on a MUT?? Don't those things generally have a 15 mph speed limit? Most do around here. Going that fast on a trail is inherently dangerous. At that speed, you ARE safer on the road.
At most speeds, I think an experienced cyclist such as yourself is safer on the road, especially at this time of year when paths are crowded with kids, dogs, runners, in-line skaters, and folks who have no clue what they're doing on a bike. Oy. I shiver just thinking about it.