Factual error: When DeNiro scouts out the building by going inside, Ed Norton guides him via a handheld two way radio. Having been a Marine for 5 years and working with various high power communications gear, I have never seen or heard of a handheld two way radio that can talk to another radio that is underground and quite a distance away. Both of the radios were portable meaning they had small batteries powering them, not a powerful power supply. Handheld radios work on the UHF spectrum, which is line-of-sight. It is impossible for a UHF signal to reach a receiver by going through numerous walls and metal piping. Ever lose your signal on your cell phone when inside a building or tunnel? Same concept.
Factual error: The computer hacker says: "I was cruising around Ironclad's server at the root cobol level. when someone counter-cracked me, hacked into my machines, my data. For three minutes, I was fully exposed." The term "root cobol level" is completely made up, and has no meaning to a computing professional.