Yeah, I'm positive the guy driving the buggy didn't run into the crowd on purpose! I work with video on my job and, while I'm no expert, I do know that the same scene videoed from two different angles can show VERY different things . . . and from the video, we only see one angle. If that is the only video of the accident, no one may ever really know for sure exactly what happened.
As for why he said the yellow buggy was backing up . . . it happened so fast he, like everyone else that was there, only had a split second to see what happened. If he was sliding sideways towards the yellow buggy (as it looks like he was in the video), from his point of view, his eyes and brain may have "seen" the yellow buggy backing up, even though it wasn't.
Bottom line here is, it's too bad anyone got hurt . . . but thank God no one got killed. And even if the accident was 110% driver error, it was 110% unintentional . . . and it shouldn't overshadow all of the good work that the Shriner's do.