In SharePoint, when an item is first added to a document library, it fires the ItemAdded and ItemAdding events as expected. And if you upload the same filename to update the existing file, it will fire off ItemUpdated and ItemUpdating events, likewise as expected. However, I have been unsuccessful at determining whether this kind of action has actually occurred or not. Or, more specifically, I am entirely unable to differentiate between the following:

• An item is updated because someone uploaded a new file but did nothing to any of the form fields.
• An item is updated because someone hit "OK" but did nothing to any of the form fields.

Is there actually a way to distinguish these kinds of updates? There appears to be nothing in event properties that contains this information, nor in the version history for both the list item and the file itself. I have even tried comparing the files themselves via OpenBinary(), but in both mentioned cases I still get the same result. Thank you in advance for any help!