It's not stated that they used "remote" push notifications, maybe they're talking about local push notifications.
Also, I guess Apple only tried to reach the CEO because when you summit an iOS app, you have to give them the information a person to contact in case they need to. I guess they gave them the CEO information.
Yes: the iOS app and the server side in a weekend (and one day actually).
I'm doing mobile app development for now 2 years (and other programming stuff for 5 years) so I guess that I managed to do it in a weekend thanks to my experience.
I don't know why there is not more event happening... I also wanted to let you know that there's a tech meet up tomorrow (wednesday evening). See http://paulfwalsh.com/dublin-meetup-on-september-28th/ if you want to join.
I'll be there :)
Also, I guess Apple only tried to reach the CEO because when you summit an iOS app, you have to give them the information a person to contact in case they need to. I guess they gave them the CEO information.