After increasing the pressure in the flooded compartment, the characters commented that they would need to be rescued in a pressurized vessel or they would get the bends, however when they escaped, they left in a pod with no hatch and immediately exited upon reaching the surface without concern over the bends.
When Cabe first surfaces and looks at his watch, it shows the time to be 2:56 pm. However, after he sets off the flare and looks at his watch shortly after (after the commercial break), it shows the time to be 2:55 pm.
After Walter and Happy board the submarine and they are getting underway Captain Steven Jones gives the order to "Dive the ship" rather the correct order to "Dive the boat". Regardless of size, a submarine is always referred to as a "boat".
The team was very concerned about how long any of them could survive the cold water once they left the sub, yet they spent significantly more time in a partially flooded compartment with water of that same temperature.
Walter draws a line showing the water level required to roll the sub. However he drew it at an angle so the water doesn't reach the line until after they had rolled.
Walt says he and Hap aren't military. They take their orders from math and science.
Obviously he has no idea what he is talking about.
Especially considering the state of the U.S. Military following "science."
Even Napoleon knew better.