Make the complaint, but the complaint most likely won't achieve anything as the screener seems to have followed a SOP used for such situations where the liquid testing is substituted by swabbing the owner of the liquids and the owner is in contact with another screening subject during the pat-down of the pat-down subject.

If you want an even more interesting experience, try being a single parent with two very young children without a stroller or car seat at the screening checkpoint when the TSA has you down as a haraSSSSment target and is running you as a haraSSSSment target. That is a case where the TSA has violated one or more of its SOPs, but there too the USG doesn't do much of anything about even such complaints.

When dealing with these petty little Napoleons, the advice is to keep your cool and not give them any excuse to point the finger of blame back at you when you mention your dissatisfaction with their behavior. Cursing out the screener isn't going to help your voice to resonate like it should.