Even with a civil case, the burden of proof is on the plaintiff. Being that the videos are the videos and the alleged victim has already testified under oath, there would be little to go with should someone want to prosecute a civil case. So the likelihood of there being a civil case is small.
Claiming miscarriage of justice is a political thing, the DOJ has no office that investigates any miscarriage of justice.
There also is no civil rights claim, as Rittenhouse did not deny anyone of their civil rights.