Not a real big difference, IMO. If he dunks the ball you score two points. If it's goaltending, you score two points, doesn't really matter does it?
If its blocked that's 2 less points.
If there are other plays similar to this where players are being awarded points when they are not supposed to be awarded points that's more.
Spread this out over the 28400 active managers, playing their 14200+ games daily...
and that's quite a few games that could be effected by this.
Now, I don't know about momentum or anything of that like being coded into the game engine, but if there is... there's a clear momentum shift blocking a dunk and then scoring, vs getting called for goal tending on a dunk, which the only possibly conceivable way I can see that is the player jumps up and sticks his hands through the bottom of the hoop to try and block the shot. Something I have never seen a player be stupid enough to do to try and block a dunk, at any level.
I understand in your opinion 2 points here or there isn't a big difference... but when you spread that out to over 14000 games each time, and several people playing in close games... (the team this happened with for me for example, has 3 games that have been decided by a buzzer beater, he's 2-1 in those 3 games), imagine if this had occured in any of those 3 games... That'd be a big deal.
You would think it a big deal if a pass interference stopped a possible touchdown that then got intercepted, but no flag was thrown? Or, if a player runs into the goalie, allowing for a shot to get past the goalie as a result and no penalty card awarded? similar such things, not a big deal really, but when you look at the bigger picture, it could be a big deal. Especially since it is being a bug (imo), and if that's a bug there, how many similar bugs are unfounded too? This could just be the tip of a huge iceberg....
MAYBE, this could be the reason why LI was so dominant no matter what to begin with?