Why is an ATC operational error called a "deal"?
The first time some of us heard this term was from a controller at a fly-in breakfast, perhaps in the early 80's.  One of the people in the group asked for clarification, and was essentially told that a "deal" was a "big deal" and that a report had to be written and reviewed, and it had the potential of being a factor in a performance rating. 

The "deal" in this case was a maintenance truck which was still on a runway, after a 727 was cleared for takeoff.  The 72 driver saw the issue and delayed takeoff, but it was on the tapes, and there were people in the cab who saw it. So paperwork was filed.

Rumor had it that the processes for deviations were relaxed for the new controllers after the strike/firing of controllers under the Regan administration.