I finished Indigo Prophecy. Towards the end it got a bit boring :/
I don't really remember the scene you're describing. Is it the one where the kid falls in the water? You have to dive after him and
just walk away when the cop comes. He'll let you go.
Check here
http://db.gamefaqs.com/console/ps2/file/indigo_prophecy_e.txt
If I could save the kid, you should be able to. The trick is knowing what
to do. I played the PS2 version so used a gamepad. When what the
walkthrough writer calls the L & R sequence comes up, you use the left and
right triggers on the gamepad (or whatever the equivalent for keyboard is)
as fast as possible. But when you're doing the CPR, the most important
thing is to do a steady rhythm and not to go too fast. There should be
some indication onscreen of what the rhythm is. You don't have to push the
joystick (or PC equivalent) at exactly the time as the onscreen
indication. You can be a second late each time, as long as you keep the
same steady rhythm.