Sorry, should have been more clear about it.
LBP2 does world space irradiance volumes for the scene - they only do RGB for zeroth order SH, and just monochromatic 1st order, so it's really not much for lighting (that's why there's no colour bleeding).
They also don't propagate the light as they just sample the volumes more in the direction of a light. It's really geared towards shadowing/occluding/light fall-off.
The quality GI will be from the pre-computed lightmap for the background (they can still move around the sun).