Job offer signed, but don't want to join .

Hi all,

My friend got an offer, company sent him email with subject "Offer letter" and the actual attachment has a subject "Employment letter" and also a "T&C of Employment" document. He signed Employment letter as well as T&C and sent to company.

There's some time still there in his joining. Now he wants to reject the offer. Before signing the docs he made sure about the following things:

1. Its not a contract
2. Its not a bond
3. Nothing has been mentioned about legal consequences, if offer is turned down.
4. It is mentioned that probation starts from the date of commencement of his services, and that either parties can terminate employment agreement by giving notice.

He has neither joined the company nor has received any property/material from the company? Is it ok to turn the offer down politely with some valid reasons?
Also if someone can recamend a employment lawyer who can go through the contrct and advice on legal aspects.
Thanks