What is the test for determining whether a jury has reached a verdict in the trial of an inmate who stabbed a deputy to death in a drunken rage?

concluded that defendant's act of stabbing the deputy was a "drunk reaction at being ordered to return to his cell and stop feeding other inmates because he appeared intoxicated," the jury also could have reasonably concluded, and apparently did conclude, that the time between the deputies' initial instruction to "lock it up" and the moment defendant stabbed Deputy Finch gave defendant sufficient time to reflect on, consider, and weigh the consequences for and against murdering Deputy Finch. (Cf. People v. Solomon (2010) 49 Cal.4th 792, 829 [premeditation and deliberation do not occur "in the 'flick of an eye'"].)