You basically have 5 options when he dthrows you.
Tech toward him. Tech away from him. Tech in place. Roll toward him. Roll away from him. Get up attack.
Zard has an answer to all of these that can lead into another grab or an attack. However, in order to keep grabbing you, he has to read what you will do. If you constantly tech toward him, he will know to dash back and grab. If you constantly get up attack, he will know to shield grab you. If you constantly tech/roll away, he will know to dash forward.
Getting out of the tech chase is all mindgames. Switch between what direction you are teching often and throw in a get up attack every so often. If you are predictable, you are dead. Another option is to try to convince him that you are following a pattern and then immediately mix up that pattern.
For example, my friend likes to use get up attack twice in a row, forcing me to either shield or to a quick dash dance into re-grab. Then on the third throw, he mixes up with a roll to throw me off because I expect get up attack.
Teching in place is usually not a good idea but if you read that he is about to dash dance quickly or do something strange you can mix up with it, but it is the easiest option for zard to cover.
Because of this, if you tech, you have essentially 2 options. If you stay on the ground you have 3, but you give the zard more time to think. Overall tho, that extra option tends to make not teching superior to teching.
Again tho, it is all mind games. Think of it as rock paper scissors where you auto lose the ties. If you make him think you are going to throw out one option and then do another option, you are more likely to break the string.