Yes, they do sometimes re-file cases that hang. But they will only do that if they had an 11-1 to convict.
Important takeaway I think is that Durham had to file this case there. Did they hope they could get a conviction? Or was it more important to introduce the facts to the people, in this lower level case, regardless of hopes for a conviction? You gotta start getting the facts out in public somewhere.
Lose in lower hanging fruit case(s)? Can still use testimony later for bigger game. Imho