Not always will you have a quality camera to get crisp HD videos or photos. Case in point:
I was fishing a few years ago, and hooked a bass. as I pulled the fish to the bank, I heard something. I looked down below where I had just pulled the fish from the water, and saw this big snake had grabbed this very big frog. I quickly released the fish, and pulled out my cell phone and began to record what was going on. You are only seeing a little over a minute of the action and it was a little late and the struggle went on for over two hours and into the night. So I could not get the whole thing recorded. I even did the editing on Windows Movie Maker.
This is just to make a point that not always will you have everything you need when the need arises. Sometimes you just have to go with it and get the best footage you can. And if you are lucky, you get something like this!