MY toes are dislocated? How TF he'd do that from SC?
Seriously, just spotted this for the first time, and unfortunately, I can't give you a concise answer. Not without pissing off the attorneys in your state.
OK, no really seriously, the answer will depend on just what happened and what the laws of your state are. Plus there is at least the possibility of federal claims, such as violation of civil rights. I have only the faintest understanding of the latter, so I couldn't tell you whether there is anything to the hash out in federal court or not. Some times it's just a matter of strategy, such as whether one court tends to be a hostile place to litigate such matters while the other is pretty decent.
As for possible state claims, I'd have to do hours of research on SC law to begin to be able to opine on the likelihood of success for a lawsuit. Generally if it's an accident and the LEO in question was using reasonable force and was also taking reasonable care (i.e. not acting negligently), I'd think he/she would be in the clear. However, SC may have specific laws or appellate decisions addressing that as well as what kind of immunity (usually limited) LEOs have in performing their duties. Furthermore, there would seem to be a significant issue of contributory negligence on behalf of the suspect, which could potentially reduce or even wipe out any award (again, this would depend on SC law...some places rely on a percentage calculation for contributory negligence, while others--at least in some instances--utilize a rule that any contributory negligence negates a claim...or at least a few did last I looked into the subject).
Additionally, going back to the facts...there is a reason you guys write reports. It's so the rest of us have an idea of what the hell happened. Until I saw statements from the three perps and your colleague, I really couldn't assess what likely transpired. And as you know, any kind of physical scuffle or alleged assaultive behavior usually happens in a short span of time, with eyewitnesses giving stories that vary anywhere from a tiny bit to miles apart.
Yet all of that still boils down to whether the guy or an attorney with whom he consults can extract any money from the county, state, whomever.
I had a client years ago that tried to sue me basically to try to extort a settlement. He had already sued other parties, got $500 (or so I've been told) from the county just to shut up and go away, and he tried to sue me and 2-3 other attorneys. He completely fabricated his claims (some of which were clearly refuted by the record), screwed up service on me three ways (served it by mail, after the court denied him permission...to a PO Box...at my place of work). The 3 year statute of limitations had expired over 3 years before...in fact, it was closer to seven years after the trial. Plus, he filed it in a different county and then missed deadline after deadline set out by court rules for certain documents and hearings.
I had to spend hours of my own time, burn vacation time, spend a bunch of my own money, etc. to defend myself. Insurance wouldn't cover it because it was way past the statute of limitations. Not that I'd want to make a claim anyway, as that would have screwed my rates.
We finally made a motion (the attorneys representing the other parties with me there pro se) to dismiss the week before the scheduled trial date. The judge came out into court, addressed the lack of proper service, then wondered aloud whether she could even dismiss it since it had never been served properly.
It was all I could do to keep from rushing the bench to smack her.
So...did you buddy do anything to expose himself to actual grounds for a suit? I'd need more facts and a better understanding of the applicable law to know. Would having a feeble case prevent the perp from suing? I'm sorry, you must be new to America, right?
There...now hopefully I've kept you off the streets and out of trouble for five minutes. Go warm your butt.