They should have started and run over the furry-tailed rat.
With how many hundreds of moms and kids watching? Look, I know that squirrels are just as dirty as rats and out of sight of the guests, I am sure Disney has a much tougher policy, but hey... why ruin the kid’s vacation?
And if they did squish the wee beastie, you could be damn well sure that somebody would have sued the park for emotional shock and trauma. Disney would have had to spend millions making the suit go away because of all the shocking bad publicity.
The driver did the right thing, IMHO.