This has little to do with the robustness principle, however mis-stated. It's just shitty design. But if someone was still hell-bent on invoking it, then if any

This has little to do with the robustness principle, however mis-stated. It's just shitty design. But if someone was still hell-bent on invoking it, then if anything, it's a straight-up violation of the adjacent words "be conservative in what you do"¹, and further disregards the commentary in RFC1122²: ... assume that the network is filled with malevolent entities that will send in packets designed to have the worst possible effect ... [1] https://datatracker.ietf.org/doc/html/rfc761#section-2.10 https://datatracker.ietf.org/doc/html/rfc761#section-2.10 [2] https://datatracker.ietf.org/doc/html/rfc1122#page-12 https://datatracker.ietf.org/doc/html/rfc1122#page-12