A crime ... for a $1, maybe $2? For the love of pete ... don't enable these people by agreeing with them. Call Mickey D's corporate headquarters and they will probably send you coupons for ten times the amount. You don't call 911.
A crime of $3 or $5 to someone could be as important as a $100 fraud committed against someone else.
You could be right that McDonald’s corp would have treated her better than the clerk/manager was treating her. But it is still a crime when someone takes your money under false pretenses and when someone is committing a crime against you, one option you have is to call the cops.
You would perhaps think she should have reached over the counter and taken her money? You would perhaps suggest she assault the clerk. She did the right thing. She called the police. The guy was wrong to cite her.