I've been focusing on false positives, so here are a few false negatives.
Actually the first one is just blaming the victim.
He sees I'm about to overtake him, hits me once to slow me down, again to get me off the road.
I get 3 sec penalty, he doesn't get anything.
In SR.B it seems every other car I pass tries to bump me off like that. Most of the time no penalties are issued, probably why so many people do it. Luckily I normally don't get a penalty either, however in the above example he went off the road after his second bump.
Now this:
He bumps me three times making sure I'm off the road. His third bump slows him enough to recover while giving me enough speed to end up in the wall at the end. His pass is successful, no penalties were issued.
When I called him out on it, he said I was a poor loser and lost control of my car..
Back to the fun stuff. Right at the start I'm behind a nervous driver slowing down too much while I have an impatient driver pushing me forward
The car behind bumps me into the car in front, I get 10 sec penalty, nothing for him, no one went off road.
That was not all. The car in front can't hold his line in the next corner and I can't slow down enough since we're both recovering from the previous collision.
He comes out fine, I lose a place and get another 10 sec penalty and another tap from behind from the first driver.
I'm the big bad dirty driver here with 20 sec penalty and a red B at the end, rest all blue... (I was the only DR.A)
So that's how I got to SR.B where matchmaking put me with increasingly unstable drivers. For example:
10 sec penalty for brushing his bumper while braking. It's not even perceptible, no collision indicators.
I'm not giving up on the challenge, I'm back to SR.A, 70, at the moment. It takes a lot of blue races to recover from 1 red one.
Edit: Just after I get back to SR.S I get rammed again while over taking. It was a DR.C driver, I was ahead yet he knocked me into the wall and on the rebound it looked like I hit him. 10 sec, and back to SR.A. The penalty system needs to look at the entire incident, not just the individual contacts. It probably wasn't malicious and he simply lost control as he was half on the grass, likely oversteered. Yet give the DR.A a race crippling penalty.