Thanx Feralidragon. Yes, that's true that we need proofs - myself was named as cheater couple times, because was much better than rest. And myself thought for some much better players than me, that they cheat. I watched some as spectator and with behindview. Did not try demo recording online.
But will do some, I think ... Funny thing is that I tried probably oldest cheat (only one I could DL) on some servers, and it worked where was no some protection - mostly to see how it looks and for better recognizing cheaters, and I won 2 times, then people said "gg"

I just replied "Not gg" . Then , when I played without cheat, some called me cheater
That would be easier part to recognize cheaters using some aimbot, but there are other cheats, not so well visible - and kept as secret, it seems. I just found something while googled, and it seems pretty advanced, and old pure scripts detect it not, at least according to what site says.
In any case, server should make clear their policy with players. What billybill says is just another case of lame administration - don't want new players ?
Make it accessible with password, or at least write that new people is not welcome, especially if they can beat old members
Anyway, all this is just sad. I don't remember so many cheats, cheaters from phone UT era, 2000-2004 in my case. Maybe should move on CTF and other team play servers instead DM ?