Dear tcain84,

One small grammar mistake does not result in automatic rejection. Depending on the error, it might be easily overlooked or be viewed as insignificant. What is done is done, so you should not fret over it. You can try to contact the school and ask to send an updated version--tell the truth that you noticed a small error. The school might agree or might say it is too late. Either way, you will know you have done all you can and be confident in the overall quality of the application package.

Good luck,
Lisa