I see the D calling Dever as a purely tactical move to get one key phrase in the juror's minds....and it was only the question that needed to be aired, any objections or move to strike was expected and did not stop the bell from ringing. AJ's question was about the Blue Wall of Silence: per....
Just after Min 57:00
And the jurors are all from the same county. They know exactly what the phrase meant and they had just seen an example of the duplicity that keeps the wall from crumbling. Canton PD, MSP, BPD all adopt the color scheme even if their uniforms are different.
JMO