[kstenerud]

Once again, it comes down to a difference between what each person considers an appropriate apology. What you usually see (including in this case) is an apology, followed by people arguing over whether the apology was sufficient or not. "Sincerity" is gauged based on whether you think the apology is good enough. If not, the usual response is to say that the offender obviously didn't care enough and is being insincere.