Originally Posted by Joliet John

I don't think all PCB connections are done by machine. The boards are certainly done on a wave solder machine, but the component connections, as far as I know, are still very often done by hand.

In this case though, with the bad connections always in the same spot, I could see that being an issue with an automated process. If people were involved, it would likely be more than one person adding those particular components, so you'd see more variety in the look of the finished solder joints.