Hey Bc,
I'm a disabled veteran as well. From one disabled veteran to another, hat's off to your husband for the service he has made to this country and some of the sacrifices you guys may have endured in the process because of it. I can relate first hand, hang in there and keep pressing on. 
The first question to ask is if you guys have disabled veteran plates. If your husband is rated 50% or higher by the VA, he is entitled to receive Disabled Veteran Registration/Plates from the state of Texas. The first registration/plate is $3.00 for the first vehicle, the second is the normal cost of registration. I believe you can have up to two vehicles registered with disabled veteran plates...you may want to call the DMV to verify that. So if your husband is rated with the VA at 50% or higher with service connected disability/disabilities, he'll be entitled to purchase a disabled veteran registration for $3.00 from the state per year for his vehicle instead of the normal cost of registration paid each year. There is a reason why I am explaining this information, I promise...
With having disabled veteran plates, it allows one to park in accessable parking (handicap parking) in the blue lots next to the stadium because of his/her disability. You can find information here on Govenor Rick Perry's website regarding disabled veteran plates and not needing the handicap placard. In 2007, the state of Texas ruled that disabled veteran plates would suffice as recognizable enough for one to park in accessable parking without needing handicap placards (ALTHOUGH a disabled veteran can purchase handicap placards should they so desire at their DMV for a minimal fee of $5 per placard) : http://www.governor.state.tx.us/divisions/disabilities/resources/parking/faq
"Veterans with disabilities: People who have a 50% VA service-connected disability, or who are surviving spouses of a veteran with such a disability rating, may purchase special "disabled veteran" license plates from the Texas Department of Transportation. Texas law allows people with "disabled veteran" plates to park in accessible parking spaces."
Below is a pamplet the Govenor's office mailed me after inquiring about the matter. I am scanning it and placing it on here for you to see:

You can also find this information on the txdot website or going by to your local DMV.
Now, that stated, the Cowboys allow disabled veterans to park in accessable parking in the blue lot at GATE 6. It is a first come first serve basis so you have to get there early enough to secure a spot. Otherwise, the best option is to probably go on ebay and buy a parking pass if you feel you don't want to risk the "first come, first serve" basis. I asked the Cowboys if they sold accessable passes and unfortunately they do not. It would be nice if they did for folks like us, but unfortunately this is their protocol.
I hope this answers your questions. If you have any more about that or the disabled vet plates, feel free to message me, contact the Dallas Cowboys, or contact Governor Rick Perry's office, the DMV, or TXDot respectably. Take care and thanks again to your husband's service to this country.