Maggot or grilled onion?

I went to Mi Ranchito today, in Lancaster, to get a burrito. I was driving and starving and had just come from L.A. and didn't have cash so I went to the drive through. The burrito was not very good, but anyway, as I was almost done with it, I found something on the tortilla that I first thought was a piece of rice, but then when I looked closer, it was transluscent and had a brown head and anyway, I am not sure if it was a maggot, but I am praying it was a grilled onion. Needless to say, I got sick to my stomach and I started throwing up. I have been sick ever since.