This link that was at the end of the second article you referenced in your OP explains why the blood work is not admissible in the criminal portion of the case.
http://www.theindychannel.com/news/24624350/detail.html
It all has to do with licensing of the lab tech, consent, search warrants and affidavits. The way the blood sample was drawn is not admissible in criminal court and it was taken for police internal investigation application only.
On a side note, I am personally not surprised that a cover-up is taking place to protect one of their own at IPD. My company tried to promote me to headquarters in Indianapolis in 1998. In an attempt to enable my wife to continue her law enforcement career I spent a year and a half in Indy while the family remained in California. I was attempting to get Indiana to change the state law that prohibits any police department in the state from hiring anyone over age 35 no matter how much experience they have. We even wrote into our proposal that such hires would be required to reimburse the retirement fund any money they would have contributed if they had been hired at age 21. Indiana is one of two states in the country to have such a law. Arizona is the other. Other states leave it up to the departments and the police unions.
We were rebuffed by the police and fire department lobbies and the state legislators who are in their pockets when a Brownsburg representative attempted to introduce the bill. It appeared their biggest concern was to protect a closed "good old boys" network at all costs. In fact, even with the tv and news coverage then Governor O'Bannon refused to grant a specific case exemption so she could be hired on. Six months later, however, the same Governor O'Bannon did grant such an exemption to a convicted drug felon so he could be hired as a police officer by the Gary PD. He apparently felt the public was better served by having drug dealers on police forces than people who have experience, great law enforcement records and are part of a good, strong family.
Needless to say, as a law enforcement family we have very little respect for Indiana law enforcement.