help with stock rear camber

[HeyNow]

I recently had PS2 NP's installed on my 135. I went a size bigger front and rear 225 up front and 255 in the back. The tires work well and the handling is good, but the rear camber looks very negative. With this setup, it will chew through the inside of the rears in no time.
I took it back to the dealer to have them look at it, and they said they could not stand the tires up any farther without adding toe in, thus making the rears pigeon toed.
Is this true, or should I take it to another shop to be aligned?