Not quite. Most were 'property disputes' but others more troubling. "...the States of Ohio and Iowa have refused to surrender to justice fugitives charged with murder,...".
Not many of us are pleased when Mexico does likewise.
That’s what I was referring to when I said, “The only grievances that South Carolina referred to was the reticence of northern states to enforce and defend THEIR practice of the Peculiar Institution”. I am not aware of any cases where murderers were allowed to escape extradition.
The only way for one state to force another state to comply with its laws - no matter how abhorrent - is through federal intervention. Yet many southerners bristled at the Prigg v. Pennsylvania decision because they viewed THAT as a federal intrusion.
Specifically, that referred to two of John Brown's sons, so again it comes down to issues around slavery.