Maybe read the police report.
Dallas.Org: El Reno Police - Report on Lona Varner
Compare it to the civil complaint.
http://www.courthousenews.com/2010/06/24/TaserGranny
The heart of it is that, according to the police, the granny was apparently an elderly woman who had gone "off her meds", was delusional, was weilding a "ktichen knife", and threatening to kill anyone who came near her including, apparently, her grandson.
Not saying they acted correctly or incorrectly - but it sounds like, if the police report is wrong, there will be plenty of evidence to contradict them (they apparently have the knife as evidence - let's see what we're talking about here). Also, I don't know, but I can see a situation where a crazy lady weilding large (if it was) kitchen knife might present a problem for paramedics so the cops had to disable her somehow. Was a taser appropriate? I don't know; I wasn't there. Neither was anyone else here.
Perhaps, just perhaps, its a little hyperbole by those seeking to argue that govt. is out of control or those with an agenda against police. They are easy targets for the both the right and the left.
Again, I am not saying the cops acted correctly, just that it may not be so cut and dry as some would like to make it.