It was just I know I mopped the whole of the floor until it was shiny, and then we were the last to leave so we locked up after I had finished, and nobody had any reason to go where I had cleaned and make a mess anyway.
Then the bloke who was the first one in this morning saw the mess there on the floor, right when I remember mopping. The mess looked like bits of powdery swarf, very easy to be mopped up with a mop, which I know I had done. So how it just got there between when we all left last night to when the bloke in the morning first unlocked the workshop, I'll never know.
It looks like I'm not taking responsibility for my mistakes or something, as due to past bullying that went on there my reputation isn't at its best, so it just looks like I'm a lazy idiot who can't do anything right, and it frustrates me.