i want to say late 2018 because iirc that's when the whole banwave stuff happened and people were making tons of bs excuses as to why they were banned. in natron's case, they and their friend circle were apparently gifting each other too much stuff.

you can find the screenshots in older threads but what happened was they posted on the forums about an imperial scroll they'd gotten, saying they traded cs:go stuff for it. when people called them out on it they backpedaled super hard making all sorts of dumb excuses but got banned anyways. and then made some more excuses.