On the crawling ticker at the bottom of the screen. the Dow-Jones Industrial Average never moves away from 18,132.7x all day. In some scenes, it's down 0.01 points, but daily trading ranges are never that narrow, especially on a day with dramatic news.
According to the dialogue, Kyle's hijacking of Lee's show happens four weeks after Friday, March 6, which would have to be 2015 because 3/6/16 is a Sunday. Thus, the main events of the film happen on Friday, April 3, 2015, but the stamp on Walt's passport has a date of March 31, 2016.
The day of the week of the show Kyle hijacks is said to be Friday, but the video of Walt and Mambo identified as happening "this morning" is dated 3/31/16, which is a Thursday. Also, earlier dialogue regarding March 6th as being on a Friday and the hijacked show happening four Friday's later means the date for "this morning" should have been 4/3/15.
Walt Camby was said to have been flying home in a Gulfstream Five but instead was shown to have flown back in a Gulfstream Four. You can tell by the non painted Gulfstream engine section.
The wireless, handheld camera Lenny uses towards the end of film wouldn't be able to transmit while in the elevator. Unless receiving equipment was placed along the route between the studio and Federal Hall, and again inside Federal Hall, he wouldn't be able to transmit from there, either.
Under no circumstances would a television network broadcast a live signal from a studio taken over by a man with a gun or bomb. They would immediately cut to black, a trouble slate, or a commercial break, and would not return regardless of any threats made against the show host or studio crew. The show's director would have no say in the matter.
It's unlikely that the commissioner would have been on sight throughout the whole time. The commissioners are supposed to run the day-to-day work at the station. Not to be involved on the field.
The stock ticker under the televised scenes shows only a small loss on the Dow the entire time. Any attack on the financial media would provoke a strong selloff, at least until investors figured out they weren't the next terrorist target.
At about 23:00, when Kyle puts the gun to Lee's head, the trigger is pulled all the way back, but the hammer has not dropped. The safety is not engaged (the safety switch is horizontal, not slightly up-angled into the slide catch notch). I suspect this is a modified "prop" gun. Still.....if it is supposed to be a real gun, the scene is factually incorrect. But, I am open to correction.
After Kyle finishes the conversation with Diane Lester via TV, he is clearly releasing his left thumb holding the "dead man's switch", making the red button clearly go up, which should have detonated the explosives.
However, since it was later revealed that the bomb was a fake, releasing the button at any time would have done nothing.
A company does not make money when its stock goes down; the stockholders, in fact, lose value. Walt Camby loses money if the stock price of his company goes down. But since none of that was Camby's intention, or shown or discussed in the movie. Camby was trying to borrow his company's portfolio to fund a secret inside trade, which didn't work out the way he planned, so he lost that investment and couldn't pay back his company.
When the two Icelandic hackers set to work, they both stop playing Just Cause 3 (2015). The game continues behind them, even though no one is holding a controller.
When challenged, Walt says that he did nothing illegal and it's "just business". However, in order to run a trading company, he'd have to know that shorting his stock before switching the algorithm off is textbook insider trading, and is highly illegal. Of course he could be deliberately lying because that's what he does, but Gates should also know this. Later when his charges are being read, insider trading is not mentioned.