What a tragic loss.....
According to Manx radio, Dave jeffries had apparently been contemplating whether he could pilot the big T.A.S. GSXR 1000 through the left hand approach into Crosby, without backing off. ie. about 160 mph. By all accounts a stricken rider dropped oil on the race line approaching the bend, causing Dave to lose control and hit the wall on the right. (2m 11s into the lap in this video).
He was a great rider to watch, a big guy who physically muscled the bike around, and it would have been good to have seen him mix it with McGuinness, Martin, Anstey, Cummins, Donald, Rutter etc........