There’s plenty of ways that an IC can misconstrue managers not acting on their advice, and usually they come down to a lack of understanding the organisation, or immaturity. Having learnt a lot of those lessons the hard way throughout my career, I’d like to think I usually don’t fall into those traps.
The most common one I’d say is when an IC thinks whatever they’re concerned about is much more important than the organisation thinks it is. In such a situation, as long as I’ve communicated my concerns to the right people, I never have any bitterness about an organisation accepting risks I’ve raised after proper analysis (unless of course, it has some impact, and then they start politically back pedalling the risk acceptance).
Personally, due to the nature of my work, I am often brought in to contribute to projects that are either well under way, or nearing completion. I will often find things that I think are risks or other issues at this stage. Any time this happens, there’s a whole bunch of things that could explain what I’ve found. Perhaps I’ve made a mistake in my assessment, perhaps there’s some mitigation (planned or otherwise) that I’m not aware of, perhaps they already know about it and have accepted it, perhaps there’s some major constraint I don’t know about... So I ask around and try find out if there are any easy answers. If not, then I’ll escalate it to other stakeholders. Usually phrased something like “I’ve noticed this, I think it’s an issue for these reasons, and could potentially cause such-and-such an impact”, sometimes with “I’d suggest we consider this alternative approach” and potentially “I’d recommend delaying delivery of this project to address these concerns if necessary”. Even at this stage, I don’t know all the facts, so I simply express my thoughts without claiming to have any definitive conclusions, and trying my best to qualify them with where I believe the limits of my knowledge/understanding are.
In a well run organisation, this will result in my concerns being proven either founded or unfounded, previously known or previously unknown, and some sort of action could result (even if that’s only risk acceptance, further investigation, or plans for future mitigation). In a dysfunctional organisation, my concerns will either be dismissed off the bat, or pointlessly argued about by political actors.
In my experience the latter reaction will usually come from incompetent management trying to conceals their failures, or incompetent contractors trying to defend their billable work. In the first case I’ll just make plans to leave the organisation. In the latter case I don’t really care. I’m a contractor myself, so my job is to deliver value to the employer (who would usually be happy with me in such a situation), I’m not particularly concerned about whether my work satisfies other contractors in that respect.