I am sure a lot of it just boils down to personal preference and what you feel comfortable with.
I have used flat head screwdriver, and short handle diggers like the one in the previous post many times in the past and they work well enough.
But if you are reckless with them you can sure mess up a root just the same as you could with any digging tool if you are not careful with it.
What ever you dig with you need to be able to control it well enough that you can dig exactly where you want to dig and not chop up the roots.
If using a long handle tool is a bit too much for you "control wise" then by all means stick with something you can control and dig exactly where you want.
The main thing when using a larger tool like a long handle hoe is to only put that blade in out far enough from the root system so that you just loosen up the dirt out around the edges of the root system, then you extract the root with your hands/fingers.
If you watch how Billy dug that BIG 4 you will notice he worked up a circle around the plant like I did and he stayed plenty far out from where the stem went into the ground while doing that.
Of course the larger the top the wider you need to make that circle dig allowing for a larger root system underneath.
But once you get it all worked up and loose, then go in with your hands/fingers and get the root out.
Plenty safe as long as you do it right.
If you get reckless and just chop around anywhere out of control does not matter if you are using a toothpick or backhoe you can mess up a root either way.
Some things I really like about my long handle hoe is:
1.. also serves as a good walking stick
2.. rattlesnake/copperhead - got what I need to deal wiht that
4.. you can sure beat the briars and stinging weeds back
3.. useful when climbing very steep places (see youtub vid below)http://www.youtube.com/user/YTTNhunter#p/u/8/x2a6a1FnDWI