The ATC guy concerned will have a rather short further career, I suspect.
The FAA is all over runway incursions now.
Years ago, I was waiting to cross 25R at KLAX in the dense fog, and after being cleared to cross, I had a close listening watch on the tower frequency, and heard a DC-8 on the takeoff roll.
I held short...and noticed the DC8 appear out of the fog, thru the intersection, and just begin to lift the nosewheel during rotation, before it disappeared into the mist once again.
Not good...
