you can't stop anyone from making claim against insurance once they prove collision occurred

filling claim and successful claiming are 2 different things

in order to successfully claim, you need to further proof that
1. the other party is at fault
2. you have documents to proof your claim (medical report, medical bill, repair bill...)

I am assuming biker is asking RM700 directly from the driver

So the next question is, if you pay him RM700, can he still claim against your insurance?

The answer is Yes

My suggestion is to lodge a police report, go as detail as possible, like rider ethnicity, sex, age (estimate), bike model, bike colour... but leave out the plate number

By doing this way, you will avoid kena compound for late reporting in the event the biker decided to lodge police report against you

Once you confirm the biker has lodge report against you, all you need to do is to lodge additional police report to add on the bike plate number