I guess the cops could have sat at the table and had a nice after church chat.
They most certainly could have went into the restaurant in force and ordered meals, even without the intention of joining the bikers for an after church chat.
The LEOs could have found their own seating arrangements, or stood in line and ordered meals to go, or went out to the patio, or lingered outside in full view with all of their battle rattle adornments on, sparkling for all to see.
In fact, they could have been in all of those positions at the very same time.
An ounce of prevention is worth a pound of 5.56mm ammo, right?
It's hard to ambush someone, if you are not first in an ambush position. Occam's Razor. ;0)