Too many characters over the course of ths how 'know' Robin Masters from earlier in life, so that to me kills the idea unless you simply accept the writers revisied history and episode continuity doesn't matter. I myself fall on the side of show history meaning something and refuse to buy in to Higgins as Robin.
Yes, but what if Robin Masters is a real person? Maybe Higgins crossed paths with him in the early 60's somewhere in Europe (or perhaps SE Asia or Northern Africa, wherever) and said, "I'll write the books, you'll get the credit, we split the profits 70-30 and I'll pay all your expenses. All you have to do is make the appearances. I'll be in Oahu if you need me. Use the red line when you call." ..... Ok-ok, I'll stop now. Who knows, it could be either scenario. It's a fun mystery for sure, though!