Absolutely, I would do the same for all fathers who witnessed their underage children being sodomised.
That's it? Just anal penetration, not other kinds of sexual abuse or violence?
And to be clear: I don't think your position is ridiculous, but if you have a clear position - for example, something like the parents of children sexually abused are free to exact revenge on the perpetrators - 1) as a member of a democracy one should work to change the laws. In other words you believe that certain crimes warrent vigillante behavior. Parents of children cannot be expected to follow due process, even days or more after the event and should have exemptions. 2) these exemptions from due process should be carefully worded, so that, for example, adult victims of assaults cannot assume that they too can exact revenge. Or handicapped victims or victims of white collar crimes etc.
I think it should also be made clear what happens to those who carry out revenge on the wrong person. Their lawyers will definitely use any law you make out of the above to vastly reduce the guilt of their clients.
They made a mistake - under the horrible stress of the incident - and chose the wrong person, but they had the right to exact revenge.
As long as the boy was in prison, it was fine, he is now on the loose and a danger to the daughter or other children, again.
If he is still a danger than the step-fathers revenge and punishment was worthless. And it was a planned controlled revenge. We are not talking about an out of control beating.
Several, but mostly any that are inadequate in addressing the danger to children
1) the stepfathers actions may not have prevented anything.
2) So it is only in relation to children where you feel people should have the right to bypass due process?
Why do you limit this to situations that involve children?
If someone rapes my wife and I then rape him in revenge a few days later...you would send me to jail?
How about my elderly mother?