Much as I love my ohshiboom, I have seen one thrown and land at a really odd angle (really hard to explane, it was thrown base first, but the wobble head and the side hit at the same time while the base was still in the air, then it just went flat, no boom) and not go off at all, never had that myself mind
Then again I have had my dynatex go off on impact, it all depends on what angle it lands. FYI I wish the dynatex was rubber coated, it's had plastic.