Possible Clues:

• Perhaps trying to be bad-tempered
• Give evidence, but not if in bad temper
• Trying to be trying
• that made one cross in the way of a trial, perhaps
• Showing irritation, note written with a pen
• In a sour mood
• Fractious
• 'Trying, perhaps, to cross this (5)'
• Short-fused
• Irascible if leaving to give evidence