The time I helped rip off Goodwill (I think)

Today Scarlett and I went treasure hunting at our local Goodwill store. I found a bunch of cool stuff, including a side chair that only needs the seat cushion recovered. So I was really excited about my finds and checked out happily, even though it took forever for the guy to wrap up all the fragile stuff. When he was finished, I turned around to take away my haul. I had Scarlett in the Moby Wrap as I pushed the loaded cart with one hand and awkwardly grabbed the chair with the other. I was just starting to make my slow shuffle toward the door when an older, majorly redneck lady asked if I needed some help. I had seen her behind me, but I wasn't paying attention to whether she checked out at the next register or was still waiting behind me or just walking around. She reeked of cigarette smoke, and I'm pretty sure she was drunk at 11:30 am. But hey, I did need help. She handed me her merchandise (a notebook, a DVD, and two pillowcases) and said "Here, put this in the buggy, and I'll take this," grabbing the chair. "Let's go." Her stuff wasn't in a bag.

We walked a few steps toward the door. "Oops, did you buy this stuff yet?" I asked, trying to be loud enough for the workers to hear.

"Yeah." And we walked out.

Ok, I don't know if I believed her, but what was I supposed to do, ask to see her receipt? I can't say for sure she was stealing, but it seemed suspicious. So now I feel a little bad. Did I just aid a criminal? Am I an accessory? Or did nothing really happen and I'm just being judgmental? Did I just help cheat a charitable organization out of $6.00? Oh well, since I had just donated a bunch of stuff right before, I guess we'll just call it even...