Advice: Can Maple be trusted?
Any very large software project has bugs, and Maple has plenty of them. You should not have blind faith in Maple, or any other computer algebra system, or a human for that matter. Use the same general guidelines that you might apply to something one of your colleagues might have come up with (after a long and complicated calculation): first ask yourself if the answer appears to be reasonable, and then check it if possible. Try some special cases, a different method of calculating the answer, or verify some consequences of the answer.
In a situation where an error might have serious consequences, be especially diligent in checking the answer. You might even try it on another computer algebra system.
See also: Finding a bug
Maple Advisor Database R. Israel 1997