She doesn't manage to latch onto his throat, but she does dig into his chest and belly with her iron tipped claws. It's sort of hard to ram into somebody who is clinging to the front of you, so in practice all that happens is that Lambert swings his head around and Shamshel leaps away, with flesh blood on her claws.

Syr only proves to make this worse by summoning the magic circle under the both of them while Shamshel is clinging, which fails and hits Lambert will some kind of magical splashback while Shamshel flips away.