You can politely explain to someone that you think they are wrong now evidenced by the fact they they were proven wrong in a similar situation before.
In fact, I would argue its literally your job to do so. You’re paid to make the right decisions AND to persuade others (and to be persuadable if you’re wrong).
If it turns out you were right but failed to convince others because you failed to present all valid arguments, then you are negligent.
Sure, I agree, politely explaining what went wrong is good. Just saying "I told you so" (or similar) is different, though, and doesn't provide any actionable information. But I get the motivation to say it, so I suggest just saying it internally to let off some steam.
Sometimes you have to highlight that specific people were wrong before, particularly in a power imbalance.
Unfortunately, most organizations don’t do distributed meritocratic decision making. The hierarchical structure is often a key component of the failure lattice, and it’s attributes and effects need to be confronted directly.
