An unfortunate incident, but correctly handled. Whether the foot fault call was correct or not doesn't matter. Professional officials in all sports are still human and IMO make an incredibly high percentage of correct calls. All athletes need to follow the rules, and if supported to play (salary, endorsements, scholarships, even with just uniforms/facilities) they are indebted to provide a proper example. Bottom line, they are representatives of their sport/school/team/endorser and like it or not the modern day heroes (role models).
I played tennis on the high school team, but when I saw the total lack of sportmanship at the college level I immediately hung up the racket and drifted towards golf.
Ironically wifey and I had a talk with her 14 year old at supper last night (without knowing about the Serena affair) regarding sports and attitudes. His soccer team is melting down due to the 9th/10th graders being self centered babies and poor coaching. The boy is a self appointed expert of nearly everything (typical teenager) yet barely made the team (shares the last uniform and the manager's job). So the last 3 weeks has been a pity party of one and the more frustrated he gets the more he mouths off. The concepts of team is totally missing.