This is my best guess.
The league has said that the contracts signed in 2010 placed a risk on competitive balance in the future.
Because Dallas has a ridiculously low cap number for a player who in any other year would probably count for 3X that amount, the league has decided that Dallas has basically obtained additional cap space because they are be charged far less for a player than what his status at the time would dictate.
Dallas payed the man similar money to other players of his caliber but they used the 2010 cap to essentially eradicate about 1/3rd of the cap hit.
As a result, Austin's number for 2011 was about 2.5M (after restructuring which is obviously premeditated to a near insulting degree).
Prior to restructuring his cap hit in 2012 was less than 2M but because the 7.8M (or about) was spread out through the rest of the contract, his cap hit is once again around 2.5M
Compare that cap hit to players of his level and there is a huge difference. Average for Top 10 WR in 2011 as far as cap hit goes was like 8.5M - 9M. In 2012 it was much higher and even excluding Megatrons sky high number, it's still around 10M
For 2011 and 2012 Dallas took a combined cap hit of less than 5M for a player who should otherwise cost about 19M and they will not have to catch up on that difference at all going forward. His cap hit is below 7M from here until 2016, at which point its over 11M.
Think about that. By the time 2016 gets here, 11M probably won't be top 10.
As a result, every year of his contract that counts agains the REAL cap, he's counting for a number that is substantially lower than what the average top 10 players at his position would dictate.
They've already benefitted by the move and will do so until his contract runs out. By dumping that money to 2010, they've paid the man what the market says he deserves but do not have to see a large amount hit the cap EVER for the life of the contract. They essentially scored free cap space.
Not mention the Cowboys and Redskins had the two highest would-be salary caps in 2010 according to a PFT article I saw floating around. Here's the article.
http://profootballtalk.nbcsports.co...alary-cap-numbers-if-there-were-a-salary-cap/
What was the would-be cap that year? 126M?
That means 5 teams exceeded the cap by 10M with Dallas and Washington being at least 20M above the next closest team.
I'd bet some of the teams were handed a free pass because they could have dumped the contract and remained theoretically compliant.
But Dallas and Washington were way over to begin with and essentially tacked on a shit ton more to free up space for future years. The league decided there was absolutely no way in hell that either team would have structured that deal like that and did it only to benefit future years and did so to an egregious extent.
IMO, Dallas and Washington are not being punished specifically for what they did in 2010. They are being punished because what they did essentially handed them free cap space in the years following 2010 thus creating a risk to competitive balance. Shitty part is, both teams get knocked for it and neither team has been in a position or looks to be in a position of real contention. All that fucking stupid ass scheming for nothing and then get punished on top of it.