It's a machining defect of the main journal. It is not ground perpendicular to the crankshaft centerline.
When the machine, or operator setup to grind that journal, and also to drill and tap the cap holes, there was an angular misalignment with the block. Either the grinding/boring bar was offset, or the block was not set right on the table.
Usually, these holes are done with a long boring bar which does all journals. However, in some cases, a human may have to go back and redo one of them if it isn't right. Also, the alignment of the cap bolts affects the relationship of the bearing saddle to the shaft.
That journal is just kinked a bit in relation to the other journals and the crank. I'm betting that engine was TIGHT from the factory, but not quite bad enough to spin the bearing. it just ground away at the bearing material until it had enough clearance to run.
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