This strikes me as dubious at best. I think a more likely explanation is that his detection software is flagging anything with the path "c:\windows\SL" as malware.

He says "This key logger is completely undetectable," which is clearly untrue (he has allegedly detected it).

If it's logging his keystrokes, it's either storing them locally or sending them off somewhere else, or both. If he's as qualified as he says, he should be able to find out which (find a file that increases in size after a lot of keystrokes, use Wireshark...).