Yep. In my experience, the side to which the holes are offset is a roughly 50/50 proposition. Maybe however it's become more standardized in the last couple decades. I notice all of my newer rims have the same orientation. I've been building wheels for longer than I care to admit.


I just pulled a 36H M13II rim out of my closet to check. In fact, yes, it's the 1st hole, but only if you start with the valve at 6 o'clock. If you start building with the valve hole in 12 midnight as in the OP's first photo, the second hole to the right is where you would start. Perhaps your way is easier for a beginner to grasp. I still prefer to start with the 'pulling' spokes and the valve at the top. All the spokes end up in the same place in the end no matter how you get there -- assuming you are building the same pattern.


Irregardless of all that, I'm going with the crowd here. The most likely problem is that the opposite side spokes were all inserted one hole counter clockwise from where the should have been inserted in the flange.