Earlier quoted context omitted.
"Important" is dramatically overstating it. I've only ever seen anyone remark on adjective order in an ESL class. English is full of ordering constraints that matter. This isn't one of them; if you put your adjectives in a strange order, the worst thing that can happen is that people realize you're foreign. [1] And the odds are they knew that anyway, unless you managed to learn perfect pronunciation without absorbing…
This isn't even to take into account that we flub our speech (not to mention writing) all the time. It's easy to imagine someone saying "red... Metal... Big ball!" because that was the order that the features of the ball arrived in their mind. So there's a difference between planned speech and rushed speech, and there's piecing together what someone means through their mistakes. For another example, last night I was…
Well, I meant to; this is what I had in mind when I said "native speakers will often violate the normal constraints if they have to string together several adjectives in a row".