My question involves criminal law for the state of: Texas
I was on my way home from Houston and pulled over to pee. ( was a long way to a bathroom) Turned into a private country drive, pulled in about 5 feet in from the cattle guard and pee'd. As I was getting back into my truck a Game Warden truck came down the drive from the property and saw me. I was given a FST on the spot and passed everything except he said my eyes were "jumpy". Was arrested for PI and sent to jail for a few hours. My truck was towed and cost me $300 to get it out. The ticket will cost me another $200.
My questions:
Can I be convicted of PI if I was on private property( other than a bar)
In other words if he didn't see me on public property can he "assume" I was in public intoxicated or does he have to see me in "public"
What should I do to get a hold of the dash cam video to prove that I passed the FST?
Is it worth fighting on principle?
Was never read my rights even when I was taken in. When does Custody start? Is it when I'm in cuffs or when I no longer feel I can leave? (ie. when he began talking to me.)

