Earlier quoted context omitted.
Not at all; TAs are paid poorly, have other more interesting work (i.e., their research) to do, and spending the time to deal with 'clever' is not a good usage of time. Sure the student learnt more, but that doesn't mean this is what they should have handed in. Have fun on your own time, but don't waste the TAs time.
We might have to agree to disagree. If TAs aren't interested in students diving deeper into the course material then I'm not sure they should be paid at all. But perhaps the less radical approach would be to pay them enough such that they can take the time to judge the work on it's merit.
I'm fairly sure that executing arrays is not part of the course material.