Hi, I have a 6 month old Alaskan Malamute and use to have a husky mix. When I had my husky I was unsure of the exercise needed for the working group (I was 17 yrs old) and I happened to inherit the dog from my sister-in-law. Needless to say she escaped everything and did kill cats, rabbitts, etc... in the neighborhood, fortunately my neighbors were not so upset as to report the incident. This happened in 1-2 days. She also tore up everything in the yard, fortunately my sister-in-law moved to where she would have acres to play on and took her with her. Now I have my mal and did plenty of research on the breed before getting her. She stays inside all the time and gets exercised a lot. With any working dog you have to keep them busy or they will keep themselves busy. Fortunately we can leave her for 4 hrs in the house not in her playpen and she just sits on the couch, when we are at work she is in a 3x2 playpen in the kitchen and does not seem to bother anything unless she it trying to get out then she scratches the floor. I have noticed with her that if I walk her first thing in the morning she is wonderful throughout the day, this does not happen everyday in the morning, but she does get walked sometime throughout the day. Even when you think they are pooped out they are not, she can walk 4 miles and act like she is so tired then see a rabbit and take off like she has not exercised in days. The breed is very deceiving in that way. If you can try to exercise them for atleast 30 mins (hard exercise) per day, I know you said that is hard to do but it will pay off. I think someone else mentioned having them pull, that is wonderful, it will let them do what they are suppose to do.
As far as getting out and killing the rabbitt, make sure that your dogs did it before you get in trouble for it, it may be that this neighbor may not care for larger dogs and is trying to get them out of the neighborhood, if there are other dogs loose they may have done it. Try not to let you or your babies get a bad rap. If you need any exercises to do with them let me know, we even have things that we do when she can't go outside that keep her calm
Tasha