The best response for your friend is to invite the lawsuit. Most States $5,000 and less are Justice of the Peace courts and require the PRESENCE of both parties at a date certain. IANAL, of course, but have seen these kind of scare tactics used over and over. Most of the time the Plaintiff can't afford to send their lawyer, thus judgement for the Defendant. Meanwhile, if your friend is in Texas, he's judgement proof even if a default judgement is granted in some other venue.
As for Texas being a venue for lawsuits, that's because the State Constitution is generous toward business and copyright. As a Native of the State I don't have a problem with this. That said, the pie is only so big and those who already had a slice and see it getting trimmed by others who fail to honor the existing patent/copyright, they are justified in going after the infringers.
Tell your friend to create 3 new buttons and ignore the rest. Sorted. (One also has an absolute defense in that the "button" bore no copyright or patent at the time acquired)
Getty, on the other hand, is a ...