Well, we must have read different versions, then. In all the ones I've read, he just gets shot up with the serum, given a costume, and shoved out there. Again, TECHNICALLY you're right, but there's a matter of self-definition involved here. If you went to see two people boxing, would you call it a 'martial arts competetion'? No, you'd call it a 'boxing match'. Similarly, if you asked a boxer what he did, I doubt he'd call himself a 'martial artist' - he'd call himself a 'boxer'. He might go so far as to call himself a 'professional athlete', or something like that, but the term 'martial arts' would not be used.