It definitely feels contradictory to have both a surfactant and a silicone in your shampoo, as one should be removing the other, right? Well, as you mentioned it correctly, you noticed a resilient silicone in your shampoo. Resilient silicones can be washed away only by strong surfactants (aka sulfates). So if the product formulation contains both a surfactant and a resilient silicone, it's likely that it's balanced so the surfactant won't be so strong to remove all the silicone. This way, your shampoo will give some silicone benefits to your hair. If it appears that the silicone is 'weaker' than the surfactant, it may signify that the silicone is there for another purpose than for our hair. For example, they sometimes add water-soluble silicones to a shampoo to make it look and feel better in the hand or help distribute the product through our hair.