In fairness the transponder thing is a bit irrelevant. If he never intended to be in the TMZ and didn't know that he was, then he could hardly be expected to have a transponder.
True. But if he would have known how ATC operates, he would have known that descending to 800 feet to stay out of the way of CAT would not make one yota of difference as far as ATC was concerned. He should have contacted ATC straightaway, if necessary on 121.5.
Instead, he used "I descended to 800 feet to stay out of the way" as an excuse. Which it isn't.