Chapter Thirty-Two: That big red DFA button seems silly to me, and I went through all the rec-guides to see if we'd gotten an Amarok writeup so I might learn more. No such luck.
At the very least I wouldn't expect it to be nearly as effective as it seems here, able to actually deflect a DFA attack with no apparent down side or indication of damage. At best, I would expect you're guaranteeing the arms take the brunt of the hit rather than risking damage to something more face like. But the arms would still take the brunt of the hit. Kinetic energy is kinetic energy, there should have been at least some mention of damage to the arms when a seventy five ton mech bounced off them.
On the other side of the fight we have Stephanie Chistu fighting a skinwalker, which is treated as a typical encounter against a typical battlemech. Complete with the pilot being staggered by a head hit and ejecting from a normal command couch.
The pilot being "rattled" isn't really objectionable considering the mech. The Skinwalker is an interface cockpit equipped machine, and while pilots don't take damage from head hits like they do in standard mechs, the interface apparently blurs the line between man and machine enough that they might react as though they themself have just been hit. Such as by grabbing the area hit by weapons fire as though slapping a hand over a wound.
(on a related note, the similar inner sphere protomech interface, combined with the madness inducing plague on Necromo, resulted in blakist protomech pilots attempting to eat people by smashing them into the faceplate of their protomechs. Direct neural interface is a hell of a drug, kids)
So it's not unreasonable for a skinwalker pilot to react rattled as though he'd just been personally shot in the face, even without actually being injured.
However, the description of the ejected pilot just describes a normal guy. Who is then immediately vaporized. Interface equipped mech pilots wear a specialized suit of PAL armor, and while it would not have saved them from an autocannon slug, it would have been worth some mention. Instead, this interesting, unique battlemech is treated like just any other battlemech.
What's the point of using a Skinwalker if it doesn't get to do Skinwalker things?