There is some misunderstanding about what is considered a dismount versus a transition. Per the rules:
Movements are only considered “Dismounts” if released to a cradle or released and assisted to the performing surface.
The first thing required of a dismount is the top person must be “Released” from everyone on the ground. If top person remains in contact with a base or the back, the skill is not a dismount. The second part is the top must land in a cradle or on the floor. Landing prone automatically makes the skill a transition, not a dismount.
Log rolls must also follow Dismounts A & B, which basically say if a log roll is thrown by 1 person it must be caught by 2, and if thrown by 2 or more people it must be caught by 3. The problems we see with this occur when a single based stunt, a prep level liberty for example, is legally cradled and caught by 2 people then immediately goes into a log roll that is caught by the same 2 people. The liberty and log roll are considered separate stunts. Catching the liberty cradle with 2 people is legal because it was a single based stunt, but those 2 people throwing the log roll make the log roll a multi-based stunt, requiring 3 catchers.