[M&M Guy]

The way I understand it, the monitor can be used to "upgrade" to a flagrant foul, or see if one occured that was possibly missed, but I believe one of the interps I saw said you cannot "downgrade" a foul once it's called.

The interp I read regarding the use of the monitor involving flagrant fouls from the NCAA-W side says:
Ruling 1: This foul cannot be downgraded. The intent of Rule 2-13.2.d is not to use the monitor to verify an already determined foul. Rule 2-13.2.d specifically states that the monitor can be used to determine IF a contact flagrant foul occurred. When officials determine that a contact flagrant foul DID occur, then the call stands and that flagrant foul cannot be ‘downgraded’. When officials are not sure IF a contact flagrant foul occurred, they are permitted to use the monitor to determine If the contact foul (observed or not observed) was flagrant. Per Rule 2-13.2.d, officials are reviewing the monitor to determine IF a contact flagrant foul occurred and “when it is determined that a contact flagrant foul did not occur but an intentional personal or a player-substitute technical foul for dead ball contact did occur, those fouls shall be penalized accordingly.” The key is to review the monitor to determine if the foul is flagrant because once it is determined to be flagrant, it cannot be reviewed or ‘downgraded.’

So, as I read it, if the call was orginally an intentional, and they check the monitor to see if it should be "upgraded" to a flagrant (or intentional personal), and they determine it was not a flagrant, they cannot also change the original call to something less.