Could the piston hit the valve if a Lexus IS200 snaps its cam belt?

Does the piston hit the valves if a cam belt snaps on a Lexus IS200 1999? If there is a small 6mm washer in the piston would it just rattle around or would it damage the engine?

I bought a Ford Transit with FSH but one invoice is missing, and now Ford warranty will not cover a broken cam belt - what should I do?

I purchased my '57-reg van in July 2009. It has a Ford warranty until December 2010 and had done 25,000 miles. It has now done 40,000 miles, but on 3 May 2010 the cam belt broke. The van is at Bristol...