Uh oh, that is a major red flag that the code behind this picker is one terrible mess. It implies that the code used for the time part of the picker is completely separate from the code for the date part.
The bigger flag is how this wasn't picked up internally, given how prevalent UIDatePicker is in Apple's own apps. I'd be surprised if no one noticed, so am curious to see if this intentional and stays the same, or was truly accidental.
I had some trouble myself interacting with an iOS7 time picker but it was about confusion of how wide the active areas where.
I'm also dubious of the still skeomorphic toggle buttons. They look like something you could drag across to activate, but you need to start your drag on the toggle switch so they're basically buttons.