Re: multi-kills… No. At least not that I’m aware of. You will only have one yellow MK shot lit at one time, even if you’ve qualified multiple MK’s in one ball. And that one MK shot value is simply based on 1/20th of your cumulative mode scoring. This is why I’ve suggested a code/rules improvement that if you qualify more than one MK in a ball, that any MK shots should count for MULTIPLE walker hits – since it’s called a “multi” kill. 
So, has anyone made it to Last Man Standing yet?
For further discussion, let’s move this to the TWD Wiki thread, or the Last Man Standing thread above.
http://tiltforums.com/t/walking-dead-wiki-rulesheet/?source_topic_id=930