In the play Julius Caesar why is Cassius angry when Lucius Pella is punished for taking bribes?

Cassius was mad.

It is an insult to Cassius for Brutus to condemn Lucius Pella. Cassius had vouched for Pella in letters to Brutus, which Brutus ignored. So in a way Brutus is devaluing Cassius Word or honor. Honor was pretty huge for men in Rome.