Agree with sleeper
There is "Gear up" on the After Takeoff checklist, but in my company we don't even have an After Takeoff or Approach Checklist. Things are done as part of flows. In reality there could've been a distraction which prevented them from retracting the landing gear for a while, but this error is normally trapped within 30 seconds or so. After a minute, things would get very noisy indeed. You would(should) realize immediately that this machine isn't climbing and increasing speed like normal, "what could be wrong"? You would then employ your basic panel scan that you learnt in pilot kindergarten and would see these 3 big green lights staring at you indicating GEAR DOWN!!! Your cabin crew might tell you about "a loud continuous noise". All of this would certainly prompt you to slow down and identify the issue.
If the reporting is true, and there was no malfunction here, take both the pilots and jail them for incompetence of the highest order as they seem incapable of operating even the most basic machinery let alone a $100,000,000 jet plane.