Will cats eat themselves sick??

I fed my cat, then was busy with something for 5-10 minutes. When I looked back, her food bowl was empty and she was a ways away from it, next to a pile of vomit that it looked like she was trying to eat. It had completely intact piece of cat food in it, in fact that's mostly what it was. I pulled her away from it and cleaned it up. While I was doing that, she threw up again. I stepped out of the room for more paper towels, and when I got back she had eaten the kitty kibble that was in her puke!
Is it likely she ate too quickly and was sick because of that? I fed her about an hour later than I normally do because I had a meeting, and she usually doesn't eat all her food that quickly.
Her diet hasn't changed at all. I fed her this morning and she was fine. She shouldn't have had any access to any people food that may have made her sick, but it's difficult to know because I'm out of the room and my roommate isn't. My roomie has had cats and knows not to feed her most things. It's possible something was spilled, but I don't see it likely. She may also have been stressed. I was gone a lot of today, had a test and a meeting directly after. My roomie said she seemed upset; I spent three days last week away from her and so she may have thought I left again, but she wasn't ill while I was gone.
Should I be worried? It's been a little while and she hasn't been sick again. Did she just eat too fast because she was hungry and eager for a meal? I've only had her for two moves now but she has NEVER thrown up.

It is not unusual for cats that are fed dry food to overeat and then drink water and then vomit when the water makes the dry food expand.  You can solve this problem by mixing a little water with the dry food as long as she will eat it all that way.   You can't leave wet dry food around for more than an hour in warm weather because it can grow things.

Giving your cat canned food will usually prevent this, or if you are feeding both, give the canned food first and then wait an hour before putting down any dry food. 

She has always been fed dry food and this has never happened. She has to lose weight, too, so I have to be careful with what and how much I'm feeding her.
I would think it would be just that she ate too quickly or overate since I fed her late, but when I had to take her on an 8 hour car trip, I didn't feed her that morning (as I was advised) and then fed her as soon as the car ride was over. I was giving her more food at once then and she was eager to eat but she did not get sick.
Additionally, i almost always hear her when she is drinking, and I didn't hear her at her water bowl. I also find it a bit difficult to see her eating all her food, drinking enough water, moving across the room to be sick, and then attempt to start eating what she had vomited in the time I had my back turned.