How many people got off that aircraft and could honestly claim to be wounded??? Unless you can call a small friction burn to your @rse a wound?! It makes it sound like people were maimed getting off that aircraft...
From memory, and it's a little rusty at the moment, I seem to recall that the "expected" injury rate when using evacutaion slides is about 3%. On that basis, if there were 300 on board, there could be 9 people with things like sprained ankles, or wrists, or even possibly in extreme cases, fractures, as not all passengers have the mobility, flexibility or speed of response to cope with exiting via a slide.
There will also be shock, and disortientation, and other issues that need to be checked out, so it's appropriate to be safe rather than sorry in this case.