Seriously? Do you know how cheap it is to have a decked out flight sim in your house? Far cheaper than going through flight school. I have one. I haven't flown in ten years, but I flight sim regularly.
The ONLY thing I find that would put the word "ominous" into this pilot having a flight sim in his home scenario, would be that he's had plenty of time to practice his routes, precisely measure his fuel burn, and think through the entire scenario. Also knowing the entire airplane because he really flies it, makes him the likely candidate for pulling off this heist. He would know what breakers to pull to disable things, and his copilot is likely a co-conspirator. The two most knowledgeable people on the airplane are in the cockpit.
I find it hysterical how everyone is freaking out about how educated one must be to program the flight computer. You can teach yourself to do this on your flight sim. There could be a dozen people on board with an understanding of how to program the route. It's really not that hard. But the two guys in the front office do it day in and day out.
i had a Microsoft simulator before 9/11 and before they removed the Twin Towers from the program.
This guy practiced how to mimic another aircrafts every move like a shadow. How to find a spot he could hold, how to make two aircraft appear as one.
The plane I believe is in Pakistan.