Bit of a thread resurrection, but this may be of some use to some....
Due to not getting around to my A service by the expiry date as not been using car much (two weeks overdue), I couldn't access the service reset function via the procedure in video (I could prior to expiry). I found that I needed to press both phone buttons and whilst holding them down hit the OK button as well and that then gave me access to service data function where I could reset everything.
2013 E CLASS, W212 bluetec 2.2ltr OM651.
It's left me wondering what else I may be able to uncover by multiple button pressing....self detonation perhaps