It’s just clumsy wording. The patient appeared physically fine prior to the EEG scan, otherwise he would have not been there in the first place.

As opposed to the patient being clearly in their latest hours as a living being.

I remember listening to a podcast where they went to nursing homes and talking to nurses on how they can pretty accurately predict that a guest is not going to survive for more than a few hours or till the next week.

(Of course they explain how this is not very scientific and how sometimes they miss the mark. I forgot where it was, but I'm looking for that episode and going to post a link to it when I do find it.)