This is the one that gets me - sometimes you're forced to work with systems that do annoying things that you have to accommodate. It's annoying, but it's more important to do the thing that prevents your users from having issues than it is to be theoretically right about whether something's required by a standard.
I've dealt with many worse cases than this, where the systems I was integrating with were doing things that weren't even close to reasonable, but they had the market power so I sucked it up and dealt with it for the sake of my users. Maybe Google's wrong here, but how do you not just implement the solution anyway?