So you can't search for `traceroute` or `tracert` directly but you can search for misspelling like `tracerout` and the results page just ends up showing the search results for `traceroute` so it's not exactly a very sophisticated filter.
Well the purpose of the filter is almost certainly to prevent running the command on the server in case of an attack, not to prevent it from being searched on Google. You'd have to spell it correctly to get the server to execute it.
You can't have some strings in the URL for the main NSA.gov domain as well. So https://nsa.gov/fakething?hey=traceroute will give you the same error.