iPhone photos sync "last year", but syncs photos from way back

[mgpg89]

I'm using:
- iPhone 5 running iOS 8
- MacBook Pro running Yosemite
- latest iTunes
- latest Photos for OS X

In the iTunes iPhone sync I have the option enabled where it syncs all photos that were taken last year.
However, when I check Photos on my iPhone, there are also pictures from 2011-2012 etc ... (they actually show up as pictures from 2011-2012)

I also did a little test:
disabled this "last year" option and only sync an album or two > the older photos disappeared.
So these older pics are definitely synced by the "last year" option.

Anyone know how this is possible?

 

[mgpg89]

And some added weirdness:

When I try to create a smart album in Photos that contains all photos that were taken over the past year, it just comes up empty.
When I try to edit the smart album again afterwards, the parameter has been changed from "year" to "*INVALID* year" ...

??