Revealing mistake: After Dante's Peak explodes for the final time, the pyroclastic cloud rolls down the mountain toward the town. Harry shouts "Don't look back, kids, don't look back." and then we are shown a wide shot of the truck zooming down the ash-choked streets. Unfortunately, it's painfully obvious that this is either a miniature or CGI shot, because the truck isn't leaving any tracks behind it or trailing any clouds of ash despite its high speed.
Question: I'm asking this because I don't really know a lot about volcanoes but, at the beginning of the movie, Harry was in the middle of a volcano eruption with: rain; rocks falling etc. When the volcano in Dante's Peak erupted, it was different from before, meaning that there was no rain (but ash), rivers strong enough to break a dam, burning water, dead wildlife etc. Even at the end of the movie, the volcano still had one more eruption before it finally died down. My question is, are all volcano eruptions not the same or are they just unpredictable when they explode? It just seems kind of odd that Harry was experiencing different things in nature after the volcano exploded. I hope I explained this enough; I'm just curious is all.