However, the forging part makes it a little messy. Yes, it sucks that she did that.First, I'd have your agent call her agent and explain the situation (and provide the documentation) and see what they're willing to do. Maybe she could just give you some sort of $$ compensation to make the whole situation go away? I doubt you really want to hire an attorney, or take her to small claims? Sounds like a fairly minor issue.
Holding a grudge does not solve the problem, all it does is raise your blood pressure.
End of the contract being the end for agent involvement sounds like an exit strategy. I guess no agent has ever been suspended, fined, jailed, etc. after a closing happened because that was the end. Really?!
Lastly, if the Seller and/or her agent refuse to help, let them know that you will need to mediate first, then you fully plan to take them to court for the repairs as well as any other damages that may have been incurred. If that still doesn't do the trick, you will need to follow through.
In Colorado, under $7500 damage, the case is to be heard in Small Claims Court, where you cannot have an attorney, so make sure you have all your ducks in a row. I would be willing to bet that you won't get that far, but regardless, best of luck to you!