Joking aside, the chances of finding a cockroach in a business class flight served on board are ridiculously small. I've visited airline kitchens in different countries, and even in some less desirable locations the hygiene standards are very stringent. Could I imagine that it it is possible that a field insect could still make their way in to my salad, even with all the washes and processing that most go through? Possibly. Would it harm me? Unlikely? Would the CSD / pursar / cabin manager take it seriously and do anything they could to make thing right? Absolutely. Every airline that I've ever had anything to do with have procedures for that - including those that do BOB. Why didn't your friend raise this at the time? The offending tray / meal would have been put in a special bag and a report filled in for analysis back at base.