Perfect sense would not be going back to the gas station at all. If they drove off and stopped at the strip mall the moment, as they claim, figured out Davis was shot and hurt, why drive back to the area they were being shot at? They obviously felt safe enough to do so once they arrived at the strip mall. Oh and mugs, it's further than a couple hundred feet from the gas station to the strip mall. It was estimated to be about 400 feet by detective Musser. Still, it was far enough away that they could have dumped something en route.
The problem for their behavior, logically speaking, is coming back to the area they were shot at if they had nothing to hide. Driving off and going straight to a hospital I would believe. Driving off, and stopping a short distance away from the scene and remain there for help to arrive I would believe. Driving off, multiple passengers getting out of the car, circling around the car a bit, and then driving back. A bit more suspicious behavior. Not saying that points to them doing anything bad, just that the behavior pattern would not be something I classified as a normal response to the situation at that point. Especially not for innocent kids with nothing to hide.
Why do I think that? Assume the kids did have something to hide such as a weapon or weapon like object. If you were in their shoes what would you do? If you actualy HAD something like that, then driving off and disappearing for awhile would seem pretty bad. If they stayed at the location the entire time, then they would be caught with the object. They have to get rid of the object with the least amount of suspicion cast upon them. Again, this is assuming they HAD an object they didn't want anyone else finding. If you are in their positions what would you do? I would drive off a bit to a place I know I can drop the object off out of sight while calling friends to come grab it. Then I would drive to either the hospital if feasible (ie I know someone isn't mortally wounded) or place myself in an area that emergency help can get to me the quickest if someone is mortally wounded.
Guess what the kids did?
Now, if I was in their shoes and had nothing to hide, I would drive off to a safe place and stay right there. Call 911 and tell them where to send an ambulance while trying to solicit help from others nearby if the need was dire.
The problem is, we know that the kids were on the phone while at the strip mall. witnesses saw them on the phone. The public has no knowledge at this time who they were talking to on the phone. If they were speaking with 911 the entire time, even their strange behavior of driving off and coming back would just be what it is.. strange behavior. If phone records during that time show ANY of the kids calling anyone that is not 911 or their parents... yah that casts far more suspicion about why they drove off and came back.
So really, logically speaking, it all depends on whom they were calling at the time they drove off and came back to the gas station IMHO. Until that evidence is released, it still leaves it open if they had an object to dump or not.