When Yang was nominated for the Harper Avery award and didn't get it, the reason was because she worked in a hospital owned by the Avery foundation. So how can Meredith?
Around 13:50 when Arizona is wiping the gel off of "Izzie" she wipes it all off and in the next clip it's back on.
At the end, as Meredith and Alex are talking to Christina, at one point Alex leans over to talk into the phone. When the camera changes angles, he is back in his original position.
@ the 3:00 minute mark, when Arizona is painting Sofia's room in preparation for her return, you can clearly see that Arizona doesn't have her prosthetic leg, and her actions and stances show her natural gait and her ankle is visible.