According to the report, Tilby told several people before his disappearance that he found an "abandoned shed" by the Whanganui River, which contained antiques, chairs, a kayak and other items.
On the evening of January 23, Tilby told his brother that he would try to borrow a friend's truck to move the goods, but if he couldn't, he would use the kayak.
Tilby went to a friend's house the next morning to ask if he could borrow his truck, but his friend James had already left for work.
"Instead Jayden spoke with the others at the property, telling them that he needed to get James' truck as he had 'a mean earn'," the report stated.
Tilby also told the others at James' house he would use the kayak if he couldn't get the truck. He was never seen alive again.
At 11am the same day, a member of the public found a six-seater kayak drifting down the river with no one in it.
Tilby's mother, Diane Tattley, reported him missing the next day. She visited her son's friends, who told her about the shed Tilby found and went with her to see if he was there.
Instead, the group found police at the property, as the owner of the shed had discovered the burglary.
"Police who investigated the reported burglary noted that there was a footprint in the shed that appeared to match that of Jayden's boots," the coroner noted.
Tilby's blood alcohol level was just over the legal limit for driving, but na Nagara noted that this "may be influenced by compositional change".
"It is not clear whether he fell from the kayak, or found himself unable to get in it once it was launched," the report stated.
"The distinction is ultimately unimportant."