Winterizing Question: Is My HWT Check Valve Leaking?

Thanks for the replies! I will go over the process again this weekend and check out the HWT drain. I actually did something stupid yesterday while pumping the pink stuff through. I forgot to shut off the outside shower faucet after blowing compress air through and went ahead pumping pink stuff. Before I knew what hit me, 2 jugs of them gone to the ground while I was inside the TT. I managed to use a spare jug to finish off all the other fixtures but it sure feels like there's some unfinished business.