I don't agree with it either, but I don't think I did a good job of showing you the article that I suspect is the one you read.
Here's a link to the article that has one Yahoo reporter quoting another one, making the quote look way more official than it should have been. It's a step below a White House reporter quoting another White House reporter as "sources inside the White House". It's pretty clearly an attempt to deceive, and I wouldn't even have caught it but I was searching for it for this conversation. I didn't intend to directly question your recollection for any reason other than I had not seen any kind of statement from the NBA about it. Yahoo looked like they were trying to create one just to fill space in the Allen flop story.
The league can review whatever they choose to. Unlike the officials, they aren't constrained in any way by the rulebook. For instance, the refs may very well have gone back to look at Allen's reaction, noticed he was faking, and been unable to apply the flopping rule because they're only allowed to use replay to review the foul itself. That the reaction prompted the upgrade of the foul in order to go back and review it is kind of a comical irony of the ridiculous way the rules clash with each other.
The NBA rulebook states as follows:
The league didn't have to review that one for long. If one of the refs on the floor had clearly seen that Allen hadn't hurt his face, they probably could have called it then. I'm fairly certain that the refs think they have enough shit to worry about during a playoff game to try to determine in real time whether someone faked contact and are happy to leave it to the league office to police.