Brake shudder after new pads and rotors install

[3LOU5]

So I installed new pads and rotors on all 4 corners of our Sienna SE, as well as changed out the brake fluid with a Mitivac-type device.

I proceeded to bed the brakes using the Powerstop procedure.

Now the minivan has developed a shudder when the brakes are applied at highway speeds.

The weird thing is, I was VERY careful and meticulous in all aspects of the installation procedure: brushing out all the rust on the wheel hub surface prior to rotor installation, torquing down the caliper mounting bolts and slide pins at the correct torque values, etc. I didn't measure rotor runout, only because I didn't have the device and I really didn't think it was necessary. I've done numerous brake jobs in the past, and this is the first time brake shudder has happened to me.

So my questions:

(1) Is it possible they sent me a bum rotor, even though it was brand new ??

(2) Would replacing the brake caliper be my next step ?? There was metal-to-metal contact prior to installation, so I'm wondering if I had damaged the 2-piston front rotor when I pushed the piston back (yes, I had the brake fluid reservoir cap off when I pushed it back using a C-clamp).

Has anything like this ever happened to you guys and what did you do to solve the problem ??