Yes that is the one. I am sorry but could not find the pic and worked on memory and got the date wrong. It is still the case that he did not find the flake at this time and the blood internally and externally was not visible to the naked eye.
I will try to find out more about it later? Could it be that the blood was lifted at this stage and no longer on the silencer, it had been at the Lab since the 13th by all accounts? Cooke was often at Huntington and would have been asked to take photo's of the silencer distmatled when finished? Again i'm not trying to offer an excuse but, that's the only explanation i can think of at this moment in time.