Before deleting all the surveillance videos in Gina's computer which shows his involvement in her boyfriend' disappearance, Mark copies those files to a pen drive.
Knowing that the pen drive accessed by another person will result in revealing the crimes he committed, no criminal would make a back up copy of such videos which will implicate him to the crimes. He would merely delete all incriminating data from the hard drive without leaving any trace.
The $50 bill that Levon leaves next to the computer says on it "Motion Picture Use Only". Also, she said the fee was $1,200 but there is clearly only the one $50 bill.
A man shows Gina text messages on his cell phone. She asks him to screenshot them and email them to herself. He says yes. She does so in a matter of seconds. She doesn't need to ask him how to take screenshots on his particular model of phone, nor does she have the time to get on the internet, connect to her email, use her log in password and attach the screenshot. Gina knows how to do all this, and it magically happens in less than 3 seconds, movie time.
Mark James (Marcus Rosner) didn't remove the tracking device from the car he set on fire. The police investigating the scene should have found it or what was left of it.