There were no injuries. The property was undeveloped land , soon to be an allotment. He was not speeding or driving fast. They were driving around on bumpy, rocky land for the thrill of it! He drove across the land, not realizing there was a retention pond. His jeep broke thru the ice on the pond and they sunk and they escaped the vehicle.
What you recite are issues for trial, maybe.
You weren't there when the incident occurred, neither were the police.
The police were called, subsequently investigated, and now are expressing an intention to take remedial action.
As to the issues of injury, I submit to you many people involved in vehicle collisions don't initially report medical problems.
That, alone, isn't unusual.
Why did they not cite him that night? What does reckless operation have to do with trespassing on private propetyy? The landowner is not pursuing any charges... why would we need to see a lawyer?
Because the police chose to investigate after an investigation.
It isn't unusual for th police to come back to the scene during daylight to view the scene, investigate further, consider their findings, then choose to cite for any offenses.
The driver was on the public roadway, and somehow ended up on private property.
The driver isn't being cited for ending up on private property, but for ending up on private property.
The legal theory behind that is that somehow the driver left the public roadway and ended up on private property.
Anyway, I'm a nobody, insofar as this incident is concerned.
You are also a disinterested party in this matter, other than being a related to the driver.
I suggest you and your relative visit a licensed lawyer in your county to seek a deeper understanding.