I'm in-between on how the DMReg handled it. As stupid as this whole "milkshake duck" trope is, the DMReg knew if they didn't review his old tweets someone else would (OTOH, it is amazing no one already had). The Aaron Calvin profile was nicely done, and they included the tweet issue at the end and let King respond, which he did very gracefully. So that could have been the end of it!
Since it was inevitable (the cancer is in our social media culture for 10-yr old tweets, not only DMReg), it made sense to address and wrap it up. If anything, they could have used his response to frame a larger story (which has been written 100x since the airplane aids south africa lady) about this issue BUT then could have said "you are judged for your actions now not your 10 year old needle-in-a-haystack tweets, and so we (the DMReg) are moving on just like Mr King".
So I think the real fail here is by Anheuser-Busch. They know they are dealing with real people not corporate PR #CurrentYear PC perfectionists. So either stay out of such things and give up the "our values" and "Wow this #Brand is so funny and friendly" crap, or just expect something imperfect for everyone's past and roll with it. If he was a rabid member of Stormfront or Antifa, maybe that is a bit hot, but if he RTs a comedy central guy's tweets 10 years ago...move along. How did "cutting ties" help? Who did AB impress by that? You're (again, 'you' = an f-ing Brand) just supporting his current decision to donate a big windfall to the hospital, anyone with common sense knows that is as far as it goes, AB is not endorsing his 9th grade attempt to be edgy and impress his friends.