Oh come on, the fact that the author was able to pull this off is surely indicative of some expertise. If the story started had started off with, "I asked the LLM how to capture network traffic," then yeah, what I said would not be applicable. But that's not how this was presented. tcpdump was used, profiling tools were mentioned, etc. It is not a stretch to expect somebody who develops networked applications knows a thing or two about protocol analysis.