Back in the day I thought those laser screeds were just a gimmick for big crews

Had a weird coolant leak on a 6.7 Powerstroke last week that had me stumped for a bit

The truck was losing coolant but I couldn't find a drip anywhere. Finally traced it back to the coolant filter housing, the one with the plastic cap. The o-ring had a tiny split you could barely see. It was only leaking under pressure when the engine was hot, so it never left a puddle. Has anyone else had one of those filter housing seals fail like that?