Photoshop :: Difference In TIFF And RAW Import With ACR

I'm experimenting with a workflow, so whilst this may seem like an odd thing to want to make work, I have a genuine reason for doing what's described below:
 
I have Canon CR2 RAW files from a 7D, Photoshop CS6 13.01 64bit, with ACR 7.1.0.354, running on Windows 7 64bit.
 
1. I import a CR2 image via ACR, with no changes to any sliders; opening it as Adobe RGB (1998); 16bit
2. I then save the image as a TIFF file, leaving "ICC Profile: Abode RGB (1998)" selected in the Color section of the file save dialog
3. If I then close all files, and reopen the CR2 and TIFF image, they (as expected) appear to be identical
4. After closing all files again, I then open the CR2 and make an exposure adjustment (e.g. -1.00)
5. Using Bridge, I select the TIFF file, right click and select Open in Camera Raw. I make the same exposure adjustment as for the CR2
6. Now, the adjusted CR2 and adjusted TIFF are different. A colour shift is noticeable, and for a severe exposure change (i.e. +4.00) the shadow detail in the CR2 is a lot lighter
 
Here are two cropped areas from the files (with a 4 stop push), showing some branch/leaf and grass detail respectively. The TIFF has a greener colour cast for the grass, but much darker shadows:
 
TIFF

RAW
 
The CR2 is still a RAW file, and as such has the original Bayer pattern data, but is there any way I can make ACR adjustments to a TIFF (taken from a CR2) to behave in the same way as the original CR2?