The legal battle over a quarantine imposed in Maine of a nurse who treated Ebola patients in West Africa could potentially set a key precedent, Professor Robert Field said in TIME magazine on Oct. 30.

The article appeared the day that nurse Kaci Hickox defied a quarantine imposed by the state of Maine, taking an hour-long bicycle ride near her home.

Hickox has shown no symptoms and has tested negative for the virus, but Maine officials have sought to keep her confined until the 21-day period the virus can incubate has passed.

As the state pursues an order to keep Hickox confined, “the court could be plowing new legal ground,” Field said.  “The decision would only be binding in Maine, but it could influence the thinking of courts around the country.”

TIME also interviewed Field on Oct. 18, when he discussed travel restrictions that government officials can make legally to contain a public health threat.