To give the benefit of the doubt, it sounds like they at some point did PR for Stardock but their involvement in anything SC:O related may be minimal. Getting a subpoena is indeed stressful and annoying and potentially costly. Someone with peripheral involvement in a suit certainly isn’t going to be happy about it. Of course their involvement may have been minimal from their perspective, but from P&F’s it’s an unknown that they’d been foolish not to investigate.
In the construction suit I’m unfortunately a plaintiff in the defense subpoenaed every contractor who ever even looked at the place for any reason at all. I felt bad for them all, since some of they were just guys who came in and looked at the damage and said they couldn’t help me since it was a bit beyond their expertise. However from the defense’s perspective I understand why they did it.
In discovery I had to hand over any and all emails that had to do with any construction or remodeling of the property, even if they were just requests for someone to come take a look and maybe bid on some work. The defense’s attorneys would be remiss in their responsibilities as attorneys if they didn’t pursue any and every avenue to find someone other than their client to blame for the defect, so they all got subpoenas.
In the light of this particular suit Stardock subpoenaed a guy who, as far as I can tell, is only involved via giving the GDC interview in 2015 and making one set of pro-P&F tweets. So while the recipient of the subpoena has a right to whine a bit about it, Stardock trying play it for PR is laughable at best.