I'll have to agree that he should not have shot them. If he had em in his truck, it would have been easy to take them to animal control and let the owners bail them out, these days it can cost $100 each. You only have to pay that a couple of times before you decide to do something about your wandering dogs.....
I would find the owner of the dogs at fault as well. Those dogs should have had a fenced in area and not be allowed to run free unless properly trained to stay within the yard. Huskies and Labs are well known for running loose and causing trouble, Labs are garbage hounds and will get into a garbage can in a heartbeat.
Another tack would be to go to the owner and have a face to face with her about the problem. If the guy had been having a problem with the dogs and did nothing but grump about them killing his livestock to the owner, then he's at fault for not trying to resolve the situation in a healthy manner.
In Vermont, all the dog license fees go into a fund that pays property owners who have had livestock killed by dogs. We should have more states with those kinds of laws.