Does he repeat the same offenses time and time again? I am generally very forgiving unless the person continues the same patterns. Words are cheap without a genuine effort to avoid offensive behavior after an apology.
But not knowing you or your husband, I'm not assuming he's disingenuous. Some people are just practical in their approach - no drama, no hyperbole. Focus on his actions afterwards - if he makes an effort not to do the same thing he's apologized for, then give him some credit and accept this as one of those "for better or for worse" things <3