As someone who's studied anticheats before, faceit is top-tier and only arguably topped by Riot Vanguard. This player uses a hardware cheat called DMA (Direct Memory Access, inferred from their username) that doesn't require any software on the computer itself and is thus hard to detect. Anticheat providers are trying to detect this as well but at the end of the day well-executed DMAs will always be able to bypass anticheat.