Not what I was thinking...see Bob's post above.

It's not where they touched it but when.

The 4 criteria did not cover the items that were once listed as exceptions but are now simply written into the rule

For example, according to the 4 criteria, a throw-in situation where A2 leaves the floor in the FC, catches the ball while airborne and lands in the BC is a violation. But the former exception, now part of the rule, states that it isn't a violation.

Still not what I was thinking...

I had in mind the cases where the ball hits the official and returns to the backcourt (still a violaion when A touches it even though they were not "the last to touch it in the frontcourt" or when a cross court bounce pass from a player in the backcourt near the division line bounces the ball in the FC on the pass but the receiver has a foot in the backcourt. Still a violation even though A never touched the ball in the FC. ....