It is clear from the video that verbal commands were not being obeyed. However, that alone doesn't necessarily justify the chosen use of force i.e firing his weapon. Use of force is a discretionary process. For example, it is common within police departments to identify 3 key conditions that justify use of force (1) weapon (2) intent (3) delivery/means of use. So for example, you have plenty of cases where weapons are involved, but (2) and (3) arnt necessarily satisfied i.e someone may have a weapon but it's not clear as to whether they intend to use it and how. So in the Blake case, it's legitimate to question whether those conditions were satisfied to exercise use of lethal force.