I think @Richard Johnston is right about this. Mendix juristiction stops at the domain model so any permission issues would be related to the database not Mendix. And since you confirmed those perms are OK then it's just not finding that record.
Maybe you already successfully deleted it. If not, where are you getting that ID from? Maybe try sorting those results and scrolling (after narrowing it with some greater than or less than filters). Also something to think about is that you may have the ID for an associated object.