The listener may need the facts corrected before the regret can feel complete.

An apology that leaves the record wrong has only done half the job. The person hearing it may still be carrying an inaccurate version of events, believing something about themselves that was never true, and no amount of sorrow touches that on its own. Sometimes the repair needed is factual before it can be emotional.

When you apologise for something, consider whether the other person is still holding a false account of it. Say plainly what actually happened, especially the parts that were not their doing. That correction is often the piece that lets an apology finally land.