No exit/arrival stamp in passport - problem?

[soph]

I was trying to figure out my arrival/exit dates (I'm over 180 days but most of it work related) for my SET O ILR application via work permit. For one trip, I realized I have no exit stamp from the UK or any arrival stamp from Germany (where I went) in my passport, since I was legally living in Germany at the time. I only have arrival date stamp in the UK when I got back. I know the dates from flight records.

Will this be a problem that the date I left the UK is missing in my passport?

Is there a way to figure out what dates the UK border agency have for my arrival/exit?

Do I need to show proof, and if so, how?

I'd appreciate any advice. Thanks!