Well, I don't know anything about copyright troubles you have with epicprops and its got nothing to do with my pack.
While technically speaking, nobody holds a copyright on the Ghostbusters props other than Columbia Pictures/Sony, there's still a certain understanding of respect that is woven into the prop-making community.
The bottom-line is that taking one prop maker's work and copying it is a pretty big infraction. This act, "recasting" is not supported by the majority of prop-building communities and websites, and would usually result in the recasting prop maker getting permanently banned.
There's also additional incentive for the customer to be wary with who they deal with, as more often than note, recasted pieces aren't anywhere near as clean or as strong as the originating artist's work. Just looking at Epic Props' website, the resin pieces look rather bad, and the ribbon cable poorly constructed, with notable gaps.
It could potentially have plenty to do with your Pack, as Packs and Pack shells produced by other notorious recasters have often been poor quality, requiring plenty of extra work to fix, if the products can be salvaged.
countspatula had no malicious intent towards you or your product, he simply wished to warn you that Epic Props might have sold you ripped off/poorly assembled props.
And I have to note, looking at the photos of the Pack he's got on his website, the fins on sides of the Gear Box look proportionally wrong, as does the knob on the Clippard Valve attached to the Pack, and the motherboard appears far too big for the shell he's using.