It’s not usually the PM that has to deal with the unmanageable mess, it’s the engineer who’s still expected to deliver and gets it held against them when they can’t because of the mess.
That's only if the engineer doesn't have it previously documented in writing, on record, that any delays are due to the mess, and that the mess needs to be fixed the right way. It certainly should not come as a surprise. This is what I meant by "inform them".
In a perfect world, yes that would work. But in most places, that’s just a type of CYA and is seen as the engineer being difficult to work with. There’s never some kind of fact-finding committee that really wants to know the truth of who’s to blame based on an objective investigation. All the business side perceives is that “this person is making noise”, and they don’t want the noise, they just want the feature.
Yes, there are such people who revel in keeping their ears closed, but I do my best to not work for them. I certainly don't want to contribute to putting an extra dollar in their pocket. About half the people are this way, but the other half are open to listening.