[michaelt]

  Would any reasonable person say that the Oroville
  dam nearly collapsed?

According to Wikipedia [1], "Erosion at the base of the weir—which was expected—progressed much faster than anticipated. The headward erosion of the emergency spillway threatened to undermine and collapse the concrete weir [...] Fearing a collapse, the Butte County Sheriff's Office issued an evacuation order of the Oroville area. [...] Engineers worried that [...] damage to the main spillway could grow uphill to the point that it endangered the main spillway gates, leaving no safe way to release water. [...] By February 13, 188,000 people in the vicinity were reported evacuated. About 23,000 National Guardsmen were ordered to be ready for 'immediate deployment if the dam spillway should fail' to help with evacuation and relief efforts."

That sounds a lot like a near-collapse to me.

Of course, you could argue the authorities acted with a surfeit of caution - perhaps there was only ever a one-in-a-thousand chance of the dam collapsing, and the threshold for 'nearly collapsed' should be a one-in-five chance of collapsing. However, I think most reasonable people would say that a one-in-a-thousand chance of killing 188,000 people living below the dam is several orders of magnitude too high.

[1] https://en.wikipedia.org/w/index.php?title=Oroville_Dam_cris...