That guy will be a great entrepreneur. Serious creativity and guts. They should just have let him fly.
Read Annie Duke's book.
But let's use a reference on ethics a little more sophisticated than a poker player: Immanel Kant. Would this strategy still be a good idea if everyone did it?
Clearly not. Setting aside how few people can hide in one water closet, if nobody pays for tickets there won't be an airplane to hide on. Frankly, anyone encouraging this behavior is suspect and reflects poorly on the HN community, which is likely why your post is being greyed out.
Airbnb, Facebook, Microsoft, Uber - off the top of my head - all very prosperous and genteel now, but all came from hardscrabble rule-breaking backgrounds.