The idiom not cricket is used to describe something that isn't fair, and in this context it isn't fair for superiors to use their agents as guinea pigs in poison trials.
Context: Can't have superiors using their agents as guinea pigs in poison trials, It isn't fair
Hypothesis: Can't have superiors using their agents as guinea pigs in poison trials, not cricket

Given this context, is the hypothesis true (Yes/No/I don't know)?