Having just got back from emergency, I thought i would mention how important it is to remove the props when doing any esc calibrations, testing or what have you when in closed quarters. I've been working with drones for about 3 years and until now I was fairly comfortable around these little shit disturbers. I'm not sure exactly what went wrong as of yet, but involved calibrating the esc's through the pixhawk.
After reboot it simply throttled up full and flew at my face. I'm not implying this was a programming or hardware issue by any means, most likely user error and stupidity on my behalf. As well as 6 or 7 cuts on my arm and wrist I now have 4 stitches holding my finger together and lost about 4mm from the tip. My quad is not very large (550 mm, 11 inch props) but this is the perfect example of what ones fingers might look like when you take short cuts, no pun intended.
I wont let this ground me by any means but I think everyone should be aware and take extreme caution. Developers have made vast improvements in safety and ease of operation to make it a great hobby but there is always ways to get hurt. Hopefully people will learn from my mistake and take off your props.