Sure there is, spaghetti interface implementations, even types that happen to implement interfaces that they didn't intend to, with methods that happen to match the signature, having completely different semantics.
Those aren’t hierarchies as I understand them, nor do I understand those to be real problems (I’m sure someone has been bitten by one of those but only by the law of averages).
What are you talking about? You could do exactly this in Java or C# or Python or Ruby or JS or etc. Not sure what ”traditional” languages you’re talking about, but this is just reflection and downcasting. It’s a bad idea, but it’s unrelated to OOP.
They aren’t “hoping it implements an interface”, they use reflection to determine whether or not the type implements the interface. This is pretty much the same thing in Java or C# with reflection and downcasting, but it’s a bad idea in both languages.
