Air Drop restarts iPhone 5s iOS 7

My friend and I tried using Air Drop with our iPhone 5S's for a 2 minute video.

I was the receiver. As the file was sending, he pressed the Home button (almost 1/4 done transferring), wondering if the Air Drop would continue in the background. My phone then reset itself. (second time this happened- first time didn't realize what was going on, just saw phone reset and thought was just a temporary glitch)

Experimented- I was the sender now (34 second video). I pressed the home buttom about 1/4 of the way through. His phone acted a little weird and told me the text box was locked from opening.

Reset of phone fixed problem-for now.

On LTE.

Any body else willing to experiment and see if this a common occurence?