I believe that the reason that Dash isn't considered premined is because numerous people were able to mine from launch.
I expect that the **premine tag was removed because there is no evidence, anecdotal or otherwise, that mining was restricted in any way.
If you look at the facts, it was at least a planned instamine:
Evan was looking for c++ devs for a "for profit startup" at the end of 2013 for the launch of an altcoin.
How can you make a profit by launching an altcoin (and be sure to be able to pay your devs)?
Answer: by premining and/or instamining.
How he did it is pretty easy:
*telling people the release would definitely not be in the next couple of hours and after that do launch it a few hours later
*buggy windows binaries
*a "code error" creating 500k coins in the first hour, >1.5 million in the first 8 hours.
How can this be all an accident and NOT be intentional?