doubt regarding december long challenge

Note that when you receive an answer −1, you should immediately terminate your program to receive a Wrong Answer verdict; otherwise, you may receive any verdict. --------what is the meaning of this sentence?

This is what I understood :
if you get -1 then just terminate the program or else you may get TLE,WA,RTE,internal error etc (anything) as verdict and you won’t be able to recognize what is wrong with your code…

Does this not mean that I read -1 and I send the control to that part of code which will give correct answer(say) to that particular test case.