I think that you need more information.
The timing chain itself cannot leak oil but the dealer may mean that there is an oil leak from that end of the engine,
( the left hand end as you face the engine from the front of the car) although I have never heard of this on a Jazz.
I have heard of spilt oil from the oil filler area running down the engine and giving the impression of an oil leak.
Was this a Honda dealership ?
Vic.