I could've sworn I saw particles like that in one oil change maybe 15,000 miles ago (123k now) but I couldn't confirm if the pan was clean before I dumped my oil. Subsequent oil samples sent for analysis to a lab out here in the US said my samples looked pretty good, especially for a Kia 4-cylinder. I would see how it looks next oil change and ensure the drain pan is clean beforehand. I don't think there's much choice than just hope and see.