Injection mold marks on Carnegie Brachiosaurus

[Dinoguy2]

So, slightly random question:

I just received a Carnegie Brachiosaurus (blue and gray version, first mold) with very prominent injection mold marks on the side. (like, prominent cylindrical features on the side of the figure - two concave on the top of the flank, two convex on the bottom). Out of all my versions of this figure, I've never come across this before. Comparing it to my other mold 1 samples, I can see faint traces of where the injection mold holes are, but they're very faint and you really have to look for them.

I'm curious if anybody else had this on any of their Brachs, or any other Carnegie figures. Trying to sort out of this is a one-off mold error (like, the technician pulled the figure from the mold too soon) or if this was a general problem at some point during a particular production run that was fixed. This is also my only Brach made with the 1989-era hard, black PVC, so it may be an issue with the type of plastic and how it cooled, but photos I've collected on my side of other variants which seem to use the same plastic don't seem to show prominent injection marks (and none of my other figures from the same general era with the same plastic do either).

Thanks in advance for your help solving this mystery!