Of all the things in the world you have to worry about, I would put something bad happening to this kid at the very bottom of the list. Like other posters, I understand your concern about there being video evidence of anything, but some harm would have had to come to the baby for there to be any negative consequence to you.
Cords avulse more often than people realise. Not every day, of course, but it happens. The last avulsion I saw - well, most avulsions I see, really - is due to residents yanking too hard on the placenta and baby is still attached
(we delay clamping on everyone unless baby needs resus). You did the appropriate things to correct the action and baby was fine afterward.
Chalk it up to a lesson learned the hard way, and now you know you will always double check to make sure SO cuts between the clamps!