[Dr. Smoke]

No, I would say it is a problem with OW. If the default app is OW, it should open in OW. Either that, or some difference between how the drag-and-drop from the Address Field in OW to the desktop is handled with OW vs. Safari.

The fact that the .webloc created by dragging from OW appears as a plain-text XML property list vs. the "empty" file created by doing the same in Safari may give the OW developers a clue.

What's interesting is I can reproduce what you reported: If I open the .webloc with Finder, it opens a new browser window in OW and displays the page. That's not how it should work.