In the moment, you react.
But no-one else reacted in this way, including all the other people whose tables this woman walked past. And it's not as if even Field looks remotely scared or worried about an attack.
Rather that than allow something worse to happen. She could have been carrying acid or a weapon
No, she couldn't. She'd gone through security. Field blatantly didn't think she was, otherwise he wouldn't have left her arms and hands free, nor would he have let her go afterwards.
She was restrained and removed.
No, she was attacked and removed. There's a difference.