Only problem is, I didn't modify that top question; I answered it. FTR it was a second answer and I subsequently deleted my first answer, but still no modification to be heard of.
The status you see there relates to the whole thread (questions + answers). When an answer is deleted we don't bump the last activity date, we just set the last activity type as modified. We can't leave it with an
answered status since this would allow for questions with 0 answers to have an answered status. Unfortunately history is tracked for each post (question/answer) separately, there is no global question timeline on record, so we can't simply pop to the last state, and computing it would be, too, a bit expensive (we'd have to read & compare all posts + their timelines to compute the correct state).