Read in the context of the entire thread, I take this as a non-apology apology, not an expression of remorse or contrition. In the thread, Mallah continued to take the position that the woman “deserved” the spanking, and it appears to me that the apology was made in order to avoid future confrontation/trouble, not remorse. Moreover, Mallah also commented:

It was a mistake. Why? It exposed me to more risk than was worthwhile, and while I might have hoped that (aside from simple punishment) it would teach her the lesson that she ought to follow the Golden Rule, or at least should not pull the same tricks on guys, in retrospect it was unlikely to do so.

Remorse involves some genuine feeling of regret that one's actions had been wrong in some ethical or moral sense, not merely reconsideration because they had been ill-advised in a a practical sense.