As a sentiment, 'RTFM' isn't acceptable in a comment
Back in the days of yore on a certain popular website 'RTFA' was somewhat playfully assumed to stand for "Read The Fine Article"†. Even if we assume a different word in 'RTFM', the sentiment is not what we want in comments here on Super User.
The user in question had an opportunity to omit that part, or to phrase it more along the lines of what the CoC suggests, for example, minimally:
LoadModule is a statement in an apache config file
Or even better, as Ramhound's comment above put it:
LoadModule isn't a console command. It is something that would be contained within your Apache configuration files. There are community tools that will help you configure Apache to support SSL/TLS. I suggest you try one those tools to get you started.
It is unnecessary, and the sentiment which it conveys is unfriendly.
† Back in the day, 'RTFM', 'RTFA' and similar expressions were the norm. They were shorthand ways of conveying anything from "reading the manual will help you understand the system better and is a good idea" (most charitably), to "this is trivial, if you had read the manual you would know this" (less so), to "I am uninterested in giving advice / your question bores or annoys me" (least charitably).
We've moved beyond those days.
If you want to say that someone's understanding of the overall system would be improved by reading the documentation, say that. It's easy to do in a way that isn't unfriendly. If you want to say "this is trivial" or "your question bores me"... don't.
PS: Some folks can be frustrated by what they perceive as a lack of effort; that's understandable- don't let frustrations colour your actions
Flags can sometimes be wrongly handled
Secondarily, people are human, mistakes happen. A flag can be misread, or misconstrued; and handled in a way that you might not expect. That doesn't necessarily mean there's a shift in policy.
Any concerns about handling of these things can be brought up in the Ask a Super User moderator chat room.