2 points
Very wrong, without proper materials, light bounces would make no sense (if there would be even any)
2 points
Wrong, if you just ported the original HL2 materials, things might look slightly weird but light bounces will very much be present and it would still look better than the original renderer. Light bounces (for global illumination) will happen with any material parameters. HL2 materials had bump and a kind of merged reflectiveness and metalicness value already, and if you ported them over correctly things would look acceptable (but not ideal).
