that can happen to the best of us
i had a humming friggy washer one time, so i removed belt and couldn't spin pulley by hand, so i ordered a tranny, luckily i saw the nail when i went to pull the agitator, so i wasn't that far into the job
but the customer waited days longer than they should have to get their washer back

the best guy on his best day can still make a mistake

but i'll never make that one twice