Wow, thanks so much to everyone on this thread for sharing. I'm a 2L and newbie to LS. This information has been very helpful in my understanding of how the legal community is being affected, and in turn, reshaped by this pandemic.
Provisionally accepting offers will not affect your other offers. Additionally, if your Windsor offer goes firm after July 1st (or is it June 1st?) you will be required to pay the deposit even if you choose to go somewhere else after that.
Also might have something to do with the fact that he inherited a fully functional and highly profitable law firm from his Father, although you do have to give the guy credit for taking the firm to the next level.