"Sorry to have bothered you!"
No... I use "麻烦您了" most often as a politer 'thank you'. One expects the other person to help, after one uses "麻烦您了" , and the story continues.
But "Sorry to have bothered you!" in English seems to end the conversation right there.
So in my opinion, the translation is really really odd.
麻烦您了 can be said before or after the help begins, although there is 了. If it is before the help, it would be better that the helper have already accepted the request.
I think the same can apply to this English sentence.