There is no pilot shortage at DL or any of the majors. What they did is easy to do but you have to work at it . Follow the proper procedures and it is hard to screw up. Take the short cuts and not follow procedures and it is easy to screw up.
Penalty will range from retraining ...probably. To termination. Depends on what they say and what they did.I have flown in there a lot and it is a hard airport to find. Especially when that large long runway is in plain sight.