E.g., here (possibly in other places) https://w3c.github.io/IndexedDB/#convert-a-value-to-a-key the ArrayBuffer might not be detached but the view might be out of bounds, so, checking just for detachedness is not enough.

IsDataViewOutOfBounds ( https://tc39.es/ecma262/#sec-isarraybufferviewoutofbounds ) sounds like the relevant operation here.