But lets assume that he really suspected that she meant physical harm and pushed her. At that point, until she gets up and tries to attack (assuming that was her intention to start with), the threat is assumed to be paused.

Correct, except for

and tries to attack

She doesn't need to try to attack. He merely needs to reasonably believe she is continuing her attack.

the threat is assumed to be paused.

While she is on the ground and unable to attack, that is true. If she stayed on the ground, he would have no justification to continue. But, she didn't stay on the ground. She was back on her feet and beginning to stand when she was kicked.

Otherwise what is the difference between one kick and ten kicks?

Kicking the attacker before they attempt to continue their attack would not be justified.

If an attacker keeps trying to get up and fight 9 times, the 10th kick would be justified.