I think the 1 shell rating seems a bit harsh, especially considering he gave it 5
in the mental category and 3
in the sedative ranking. It sounds like it was a strong, sudden kavain rush that hit him. Might be really sensitive to it or had too much too fast.
He might consider it a 1 shell kava for his own usage, but from the description alone, it's obviously not.
I think 1 shell ratings should be saved for kava's that almost have no psychoactive effect at all, even at high doses.