If You Know Anything About Indiana OWI Laws

If someone could help me with this it would be amazing.

"Frank" was pulled over today and suspected of possesing some bud.
He was given a field sobriety test and was told he "actually didn't do that bad" and was assured by the suprisingly, cool as hell, officer that he wasn't going to jail and to not be worried at all.
No bud was found or even searched for, but he was taken to the hospital for a blood test.

He had smoked about 2 hours prior to getting pulled over, from smoking to blood test about 2.5 hrs.
What happens when the results come back positive for THC? Will there be a warrant issued for his arrest or do they do that just to make sure there's no alcohol?

Any legit replies would be amazing.

hold on a second..

the cops didn't arrest you for anything, and you took the blood test??

Why did you take the test if you did nothing wrong?

Hey bro I live in IN also.Well that didn't seem right.Did they make/force him to?Im not to good on the owi/dui laws here in IN.But if they didn't make him go,he waived his rights.I would have refused.Thats indiana cops though they will try anything & switch words around to get you to do what they want.
This link will help.If his record is clean of dui/owi it will be a misdemeanor.
http://www.1800duilaws.com/states/indiana_owi_laws.asp

basically if you're not under arrest, you are free to go...

if a cop wants a blood sample, he can get a court order. he can only charge you with failing to submit if you fail the field sobriety test, which you passed or you would've been in handcuffs....

Maybe the officer took "frank" to the same place the took Bisard for the blood test?