It would have been a different story for you if he had approached you through some reference or something like that and requested a reference, upfront putting the experience details in the CV.
Though, morally, it would have been still incorrect to falsify the information so he could build his career on this false premise.
Just this weekend, in Sakal newspaper, I read an article about a person who falsified his educational information while getting a job, and it haunts him in his few years of career. This guy has changed jobs frequently in the fright that he would get caught. He seeks help from the educational institute to correct his educational background, but now it is legally not possible. He has to take psychiatric consultations to get peace of mind, and he may take the matter to court just because he wants to get rid of his guilt (prayashchitta).
These are rare cases, but they happen...
Generally, organizations would just reject such candidates and go on... But if this organization is pursuing legal action, that means they have already signed some contract with him.
The person had to understand the gravity of signing such contracts before falsifying the information...
So, in my opinion, his career issues are no more due to your rejection, but his own risks... :-)
Best Regards,
Amod.