Could it be that maybe he's been having some private conversations with people who are in a better position to help resolve the situation or even that he is just tired of the negativity.
Grady has done a lot in pool and for pool. He has also been one of the folks in pool who is very very very outspoken when he thinks that something is wrong. As such there are plenty of folks who don't like him despite his accomplishments.
Who knows why Grady is offering an apology. I don't call it flip-flopping - I hate that term personally.
We see it all the time though that one group is critical of another and then later they announce that they are now partners. Companies, politicians, countries, and now, thanks to the internet, individuals, all play out their grievances in public to stir up public frenzy and win supporters to their cause. Sometimes this results in public pressure to bring the other side to the table. I doubt that this is the case here but perhaps they are talking and working something out.
In any event, there is the hope that it produces something positive.