@flo You can flag it, but it may or may not be removed. It depends upon how far away from, or how distracting the comments are. I would imagine if the OP came on the thread and asked people to refrain from giving alternate answers, that might have some sway with the Mods. But the Mods do their best to let comments stand, as long as they are not hurtful or somehow inappropriate in a NSFW manner. The Mods also might remove some off topic comments if the OP came to them in private and asked for assistance, but only if the Mods, according to their own rules and standards deemed it necessary, or if there were some other reasons (like the OP was a child, or someone with limited mental capabilities, or limited English).
I have seen the Mods come onto a thread that has gone off the rails and give a suggestion to us to us to try to stay on track, but they usually let the posts remain.
I’m not a Mod by the way, but I have read a lot of posts about what they do and why they do it. Most of what they do, seems very reasonable.