My experience with class A's is that as rule -- the longer ones are better engineered than most SUV and pick-ups. Some of the 34-foot class A's I have driven have better (tighter) turning radius than every SUV or pickup I have ever driven.
Rather than an endorsement for a RV, I would rather see that good, competent drivers of any class vehicle get a special endorsement that would provide evidence of being a "better" driver and get a break on insurance costs or DMV fees.
Every larger vehicle driver knows, or should know, the limits of turning radii and I bet that driver that turned left from the right lane did it intentionally -- are you sure there was not a turn signal from the vehicle? I have had to execute some "odd" looking lane changes myself a time or two.
The biggest pet peeve I have with passenger vehicle drivers is their lack of awareness of the required stopping distance of a 10-ton vehicle -- smaller cars frequently cut in front of RVs because they believe that a 10-ton vehicle can stop as quickly as their 1-2 ton vehicle. A couple of kids tried to slip in front of the Phoenix One (7.5 tons) one time at highway speeds and then immediately braked to turn right on a side road -- even with my brakes locked up I had no choice but to give them a glancing blow -- something I doubt they will ever forget -- the winch on the Phoenix One cleared the trunk before (nearly) making contact with the rear window of the sedan... The woman siting in the back seat of the sedan was a little concerned....
Mark