2005 Volkswagen Golf

Hello,
i have a golf 5 whose engine stops a few seconds after starting to work. The coil lights turn on when I try to start the engine again, and it does not start until I wait for a few minutes. The engine also stops while driving. I took the car to a mechanic and he told me that the problem is the injection computer and it has to be replaced. He said that this happens because there has been some water leaking on it.
what do you think?

thank you!