In my case, the o-ring didn't blow out. If fact, from outside, it looked perfectly seated in its grove and the two parts that holds the o-ring has no misalignment in angle. Except the o-ring was broken, which became obvious when I separated the two parts. I didn't realize I could test it to confirm it was bad. But I am pretty sure no way that o-ring could have kept the fuel inside. After repairing, - just got my o-ring delivered - I will test.

I have indeed the NT530. My problem is that it give "No Communication" when trying to test the engine and transmission ECUs. And quick scan tells me no error code found.

Also, it took forever, like > 5 minutes, to get VIN, establish communion, downloading info, before I could do any useful diag action when it worked.