As I understand it, either she called for backup or was deemed to be in need of it not once but twice - the second cop to report for duty was Mehserle. Also as I understand it, the taser that she was waving in Grant face actually belonged to Mehserle. And last but not least, as I understand it, the Bart Police and the Media do NOT want news of this relationship widely known.
Isn't that interesting?
Here's a snapshot of the page I stumbled upon with my magickal research abilities (no I do not do Facebook, and if less of you did I wouldn't even be considering it):
Be seeing you.