According to Skinner, CWW is considered highly skilled in the field of IT. Taking this at face value, from my experience working at large corporation with an IT support department that included security professionals, your standard IT employee was there to offer support with run of the mill computer issues (e.g. password reset, server issues, computer problems, installing new equipment) while security professionals had extensive experience with encryption, and securing data. From what we know so far, I would guess CWW is your standard IT guy who knew a lot about PCs, installing computer equipment and maintaining websites.
My point here is to offer an explanation as to why CWW failed to cover his tracks. IT and security are closely related fields, but require different skills. It is unclear whether CWW had more knowledge than the average joe regarding computer security measures and/or cell phone tracking (i.e. failure to avoid Walmart's extensive security system). Sure, it is possible that CWW had no clue about Walmart's cameras, but for some unsubstantiated reason I think he was aware, to an extent. Walmart's security cameras cover the parking lot area. Perhaps CWW did not know this and remained in the car while JR made the purchase. It would be very interesting to know what vehicle was driven to Walmart, LE surely knows. Maybe it was the van.
That being said, both a hammer and a jumpsuit could be obtained by other means with substantially less risk (e.g. small hardware store, JR's previous employer). So, what did these two need so badly from Walmart? My best guess is burner phone(s), prepaid cell phones that are not easily tracked to the purchaser/user, or money transfer services. I would assume that if either JW or CWW is on camera buying a hammer, jumpsuit, or anything that could be used to assist them in murdering TS, we would have seen 1st degree murder charges against at least one of two.