If I add an elevation to a small, wide view on Android 5.0, the shadow looks really weird. However, on Android 5.1 it looks ok. For an example, take a look at the following comparison image (please click to view at full resolution):
On 5.1 the shape of the shadow is uniform, while on 5.0 it gets thinner towards the edges of the screen. The thinner (i.e. smaller) the view, the more apparent the effect is.
I'm not sure if this is a bug on either version, however I need the shadow to look on both versions like it looks on 5.1 now.