Looking at the Nike twitter page I noticed that they not only use twitter as a promotional tool but they also use it to communicate with consumers.
Other twitter users who use #strongeveryrun or #justdoit get their tweets retweeted by the Nike twitter page. People who also post photos of their shoes or Nike gear get their tweets retweeted as well. It seems Nike adds a comment to go along with their retweets which makes their form of communication on twitter more personal and interactive.
I am sure that from seeing the way Nike communicates with twitter users, they would be very responsive to people on twitter if any form of crisis were happening within their company.