There really was a lot of mountain lion discussion in the earlier threads. I think it is VERY, VERY unlikely. I have already stated my reasons. The chances being killed by a mountain lion is something like 1 in 30 million, whereas the likelihood of dying by drowning is 1 in 1,113.
Here are some statistics on the likelihood of dying for various reasons. The chance of dying from a predator attack are so low, they are not even on the chart. :
http://www.nsc.org/learn/safety-knowledge/Pages/injury-facts-chart.aspx
Furthermore, the increase in mountain lion sightings and attacks is mostly in California, where it is much more heavily populated than Idaho. I have read some estimates that there are only 2,000 mountain lions in all of Idaho. Idaho has so much raw wilderness land and natural prey that cougars do not need interact with humans or prey on small children.