To be fair, we just don't know if there are any Western special forces in Ukraine. There could be none - but we both know it isn't possible to prove a negative. My opinion is that there are none as I think it would be hard to keep secret if they were there.
This person who might be a troll says that there are troops there like it's general knowledge. I think that's either a lie or it's general 'knowledge' (in the sense of disinformation) in news sources we don't read (e.g. Daily Caller, Facebook 'silo') but that he does.
[edit] I looked at his profile, and it looks more like a pepper than a troll. So MAGA news sources. Go have a look, pretty sure I'm not wrong here. [/edit]