Plot question

He didn't pickpocket anything. They just bumped into each other by accident. She dropped her belongings. He helped her pick them up but realized after she left that she forget her pen. That's what he was holding when he called after her. We discover later that he followed her to return the pen and that's when he saw her being attacked and shot her assailant with his concealed legal-carry gun.

A little thing you'll notice is that when Esme walks away after bumping into this man, Frank McGill, checks his own wallet in his pocket to make sure it's there, like wanted to make sure he wasn't pick-pocketed by her. A nice little touch.

A few scenes easier when you see Esme on the big screen in that public plaza in Chicago, you see a man sitting on a bench wearing a sweater with a hoodie with his back to the camera, just staring intently at her on the TV. That's the man who attacks her with the gun. He was clearly obsessing over her, the only person watching the screen, stock-still. It was a little moment you could miss, but a nice touch to show this man didn't come out of nowhere.

The whole Frank McGill element was a great aspect of showing the rationality of the other side of the gun debate. That there is value in law-abiding citizens having guns. The movie and the bill in it aren't about banning or taking away American's gun, like so many 2nd Amendment advocates assume. It's about gun CONTROL, and the man who attacked Esme is portrayed as a criminal, even mentally deranged (one would have to be attack a young woman with a gun over her first amendment rights) - he's the kind of person that the bill wants to put a spotlight on so he can't legal and easily provide a handgun. If he's intent on getting one, he'll need to go to the criminal Black market (as mentioned at the end of the film), which goes to show the movie understands that this bill won't stop gun violence in the US (nothing will) but it may make it harder for dangerous people to get guns, and in turns save some lives. It's even stated by Rodolfo that the bill wouldn't have impeded anything that allowed Frank McGill to have his concealed gun. Even though the movie is more about lobbying and the corruption in the US political system, the gun control message is - at most - that this issue isn't black and white. It's not about allowing the country to be rampant with gun for anyone who wants one and any moment for any use - it's about regulating that law-abiding citizens are the one's most likely to get their hands on them legally and if 2nd Amendment advocates opened their mind a bit they'd realize that if they are OK with just a little more regulation, they will still get to own and use their guns safely. But it seems that the only way it's viewed is that any regulation of any kind is an infringement of the constitution and thus should be disallowed, like citizens of today know exactly what the forefathers meant when they created the bill rights and there is no room for a different interpretation. This issue is so much of a Grey area than something so cut and dry. The movie makes a point to show both sides and tries to be very clear that it's about exploring the best solution for Americans safety and it's not about putting Americans at greater risk.