It's the eternal cop-out.
"That wouldn't work on the street."
"OK, show me."
"I can't, I'd kill you."
"OK, tell me about your fighting record."
"I can't, it was all on THE STREETS."
"Which streets?"
"I can't tell you."
"OK, so how do you measure performance?"
"By biting and gouging on the THE STREETS."
"Which streets?"
"I can't tell you."
And so on...