Mikhail, Please......
We know you're trying to do such a hard-work around here, But ffs, I see no reason to ban him this time. If you really banned him for using that word as a stick then I don't know what to tell you. It's not like he insulted him or insulted his family, "Fvck" is a word everyone use, until he directs it to him, then you have the right to give him a warning or maybe to ban him.
Have a good day,