The biggest issue I have with "get the job done" is that it is entirely too vague. Does it mean:
1. Get the job done in the shortest time frame regardless of quality and we'll fix it later (too often the case, BTW)
2. Get the job done with the highest level of quality regardless of how long it takes
3. Get the job done so I (the manager) can get a raise / kudos / whatever and I'll take all the credit
4. Get the job done in a reasonable manner and time frame in support of corporate goals - without killing yourself; we need you and your talents going forward, too. Just let us know if and how things change that might impact the delivery.
In my view it ought to mean # 4, however GTJD is too often left to interpretation. If that's the case where you work, feel free to "steal" the above to ask clarifying questions when approached with GTJD. Just be ready for answer 2.5, which is "I'd like it done unreasonably fast and with the highest quality because I already promised the delivery date. And can you do it for free, too?"
And kudos to Andy's nephew, who felt that keeping his word was important enough to put in the extra effort. Ya gotta love someone who takes ownership of their mistakes and follows through on their commitments. Bet he learned something about estimating from it, too! :-D
Here there be dragons...,