A few points.
a) the Enterprise appeared to be towing the Constellation in the original episode, as there is a down shot of the Constellation looking down between the Enterprise's engines that shows they are holding a relative position, and moments later Spock reports that the Planet Killer is pursuing them and that they are able to maintain their distance, and it's then that Kirk tries to beam over and the Enterprise gets clobbered. If the ship were running away without the Constellation in tow, I doubt they'd have gone to the trouble to make that effects shot of the ships facing the same way.
I'll grant you that. Still, as many episodes demonstrated, the shots don't necessarily illustrate "exactly" what was supposed to be happening, sometimes they would do the best they could to give the impression (which is why the battles as composed of individual ship shots and not composities). And since they never actually used an animated beam effect for the tractor (a feature I always liked BTW) , we have no idea if the overhead shot was supposed to represent the 1017 being towed or just the Enterprise in an "along side" sort of position. You could be absolutely right, but that's the fun part: so could I. :-)
It's the "moments later" that causes the issue, IMO. Moments later, Spock says they (which could mean just the Enterprise or both ships) are maintaining their distance.
However, Kirk doesn't even mention towing the Constellation to Spock, he even closes his communicator after giving the order to beam up Bones and Decker. He still has to "get her ready" for towing. Moments later (in the enhanced version), the Constellation is secure in the tractor beam.
The best evidence I have to support my view is the dialog regarding the tractor beam and the fact that nobody on the 1017 seems to be at all affected by the attack, since even acceleration is felt on Star Trek. However, Spock's dialog and the possibility of the original shot representing the towing could very well bring it the other way.
As much as I do really enjoy how much the episode is opened up and exciting with the enhanced effects, I generally watch the original version, transparencies, yellow phasers, AMT kit and all. I always like original versions. I've said it often (probably in this thread too), I love being able to choose on a whim.