Liquid hydrogen leaks can be ignited by the static spark set off by the leak itself?
Hydrogen flames are not visible (see slide 16: hydrogen refinery would look same when on fire as when not.
Compressed H2 gas or Liq H2 have only about 15% or 30% of the energy-per-gallon as gasoline.
And on and on... Sure casts doubt on feasibility of H2 as a medium for energy storage.
Though his point is valid - hydrogen will burn extremely quickly, we used to do these as demonstrations in school. Where a pool of gasoline will burn over a period of time, a tank full of hydrogen will burn almost instantaneously to disastrous effect - forget about rescue, the only sort of "rescue" will be body retrieval of whatever is left.
Which was done in (yeah, I know) an episode of CSI:Miami: http://csimiami.wetpaint.com/page/207:Grand+Prix
Though, of course, hydrogen is far more exciting.
"There is actually more hydrogen in a liter of gasoline (116 grams) than there is in a liter of pure liquid hydrogen (71 grams)!"
But the coolest of all is that hydrogen flames are invisible! Hydrogen flames are so energetic that they emit UV radiation! I remember when I was in grade school and tried electrolysis at home. I managed to collect some hydrogen in a test tube, and I ignited it with a match. I heard a loud bang, but no flame. Sound, but no light. That was fascinating.