I know this is a few weeks old, but here is a link to the son's testimony. I think it provides some clues as to why he was acquited. Not that I agree with it.
"Aragon was driving the children to see their mother on Christmas Day morning when the car hit ice and slid into the snow bank, Bear testified. His father got out of the car and used a small military shovel to dig the his 1988 Buick Century free from the snow.
The boy said he decided to set out on his own and walk because he wanted to find help for his father. Sage decided to go with him.
"He said 'OK, stay together and don't go into the fields,'" Bear testified.
After Sage and Bear began walking, Aragon freed his car from the snowdrift and drove back to their home in Jerome. The children's mother called later to say the children never arrived.
When authorities found the father about 10 p.m. that night, he was searching for the children at the site where the car had become stranded."
and
"Teressa Aragon, a Jerome resident and half-sister to the children, was among witnesses for the defense who testified that Aragon was a good father that worked hard to support his family and had custody of the children since after they enrolled in elementary school.
Sage and Bear wanted to see their mother for the holidays, she said, and she understood how Aragon might have been persuaded to let them hike the rest of their way on their own."
From:
http://www.google.com/hostednews/ap/article/ALeqM5j6VDKkwiyYMDb5X09CdLMLYPJnWQD9B72U3G0