Garcia's participation at the event is predicated on the theory that he flew back from the GD East Coast tour in the break between Oct 18 (Minneapolis) and Oct 23 (DC) to play this gig, and the one with Merl at the Matrix on 1970-10-19
Based on listening to this we believe this session did not occur at that Matrix, but instead at Wally Heider's as is indicated on a different circulating complication that includes this material, a JA tape called Bark Sessions.