He obviously hasn't got a glass chin, he lost on points to Maidana which implies he got hit a lot, it takes a good chin to not get ko'd after getting hit a lot by Maidana.
You can deny their existence all you want, but glass chins exist at all levels of boxing. The elite boxer is generally able to compensate for punch resistance issues against inferior opposition, but his mandibular vulnerability will be exposed as he faces better fighters.
hmmm tough choice. I love watching Khan fights because you never know whats going to happen, but then again i love watching iron chinned, on defensively weak fighters take hard shots and keep coming. I think i like them as much as each other depending on the scenario. But Amir Khan is great. He always has me on the edge of my seat.