Are you suggesting that a homeless person entered your property, tried to log into your Qubes OS machine once, failed, and then ate a candy, left the wrapper on the ground, and left?
I have encountered this in the testing of Qubes 4.2. It has been fixed with updates.
Sounds like you need this:
Unlikely, unless you had software continuously keeping that in your RAM.
So, the homeless guy wasn’t an international spy? Damn…the story was just getting good…
Look, in all seriousness, you’re probably fine. It’s highly likely that your logs will show something innocent, or possibly the bug I was referring to.
But if you’re truly worried, by all means, rebuild your system.