This is a very similar issue as this previously reported bug:
I decided to file it separately because the previous post was for a view that is not supported anymore, which resulted in a fix being declined.
In this case, if a question is self answered, and both question and answer are returned by a search result sorted by "newest", the question shows up above the answer. In other words, the question is shown as newer than the answer.
Technically speaking, the question and answer are posted at the same time, so you could argue that the sort order is arbitrary, and the displayed order is not wrong. I still think that the behavior is not what the user expects. At least I find it confusing every time I see it. An answer should never show up as older than the question it answers.
@Tim pointed me towards another related question:
One answer there suggests that complex sorting logic would be needed for this special case of self answered question. I don't think that's the case. The post type could be used as a secondary key for the sort, so that answers are always considered newer than questions if the time stamp is the same. It doesn't really matter if the question and answer are related in this context. If unrelated questions and answers are posted at exactly the same time, their order would be arbitrary anyway, so forcing them into a certain order does not do any harm.