I would like to think, and I think you state as much as well, that LEO should remain as neutral as Judges while enforcing laws. The conversation got to where it is because we were discussing why some may not trust the justice system and openly supporting a potential criminal defendant before a GJ ruling is handed down is not being neutral in an investigation. After a no true bill is handed down...show all the support in the world for him. Until then, an investigating agency should not so publicly show support for one side of the investigation and not the other.
I think they did that and officers were instructed to no longer wear the bracelets. Granted, they received grief for going through the proper channels for it, but it was done. But the concern would still be, ok, the bracelets are gone but is the underlying bias gone from the investigation?