Okay, sure. Forgiveness is important. But, like, first let's get the situation remedied. Step 1 isn't let's immediately forgive them without saying anything. Step 1 is holy shit look at all this blatant plagiarism going on, let's make sure people know this is happening so that the original creators can avoid having their work stolen.

Like, yeah, this guy and all the other plagiarists are people. So are all the people they're stealing from. Getting the word out and not dwelling on what they did forever aren't mutually exclusive.

You can set a boundary and forgive someone without letting go of that boundary.