It seems unlikely such an incident would be able to make the harmonic balancer slip since it is attached with metal parts. If the outer balancer slipped against the inner parts the rubber was already bad. I don't really know what I am talking about but it seems logical. I'd drive it and see if it vibrates. If it doesn't I'd not worry about it.

More noise seems like it might be you listening harder after the little slip.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.