I'm not positive but I seem to recall somewhere-someone talking about inconsistent feeding being a possible cause for that sort of "dimpling" (uneven fat deposits?).
(and I mean some periods of near-starvation, not just a few days here or there difference in scheduling). But as long as he's eating & shedding ok, & improving, all is
probably going to be OK...I'd just not be inclined to buy from that vendor again, personally. Remember that baby snakes (like all kinds of babies) don't have much
muscle tone yet, that comes with moving around more, so that's probably why it shows up like that,& once he gains strength (muscle tone) he should improve. I sure hope so.