One of the problems today, is the announcers, coaches, and players do not know the rules. The announcers (other than the former officials) think they know the rules.
I get this at the High school and NCAA D2 level. Coaches and players will complain about a call. Then make a statement about it. That statement will not be the rule at this level. Such as for High School, the coach will yell the QB was outside the tackle box when he threw the ball away. In high school that does not matter, the QB needs to throw the ball in the area of a receiver.
DPI must be in one of these categories or else it is not DPI. Arm Bar, Grab and restrict, not playing the ball with contact, grab and turn, cut off and playing thru the receiver.
OPI: Creating separation, pick, blocking downfield, and playing thru the defender.
As an NCAA official, I spend 10-20 hours a week in addition to my full time job, outside of game day and travel. I take at least one test each week (8 normal questions and 2 replay questions) Plus watch a film review from the CFO/NCAA. I have every play graded from the film, typically 140 plays per game. If I get too many incorrect calls on the season, I will not be invited back next season. If I get some items wrong (downs, 12 on the field) I will get pulled off one of my games.
We usually get the test on Thursday and the answers on Monday. Some crews will discuss the questions during pregame. Here is a sample question
2/10@B-30 Team A completes a pass for a 5-yard gain. After the down is over, Team A sends in three substitutes, and three players begin to leave the field. A88, who participated in the previous play, trail the three replace players toward the Team A sideline. The three replace players continue into the team area, but A88 stops and sets up on the line of scrimmage very close to the sideline. After the ball is snapped A88 runs down the sideline and catches a forward pass at the B-10 and runs into the end zone.
Ruling: Requires 4 items for the next time the ball is to be put in play (Team in possession, down and distance, yard to get first down, and clock status-ready/snap/running/no clock/10-second runoff/play clock)
Answer: A, 3/20, B-40, snap 25 seconds.
Reasoning(Mondays answer sheet): Unsportsmanlike conduct by A88 for unfair tactics: using the substitution process to deceive the opponents. This is a live ball foul and is penalized 15 yards from the previous spot (Rule 9-2-2-b). The clock will start on the snap (Rule 3-3-2-c)