Evelynn doesn't get stunned during E+R when she should still be targetable

Evelynn jumps to her target with her E. She buffers her R while leaping. Before she turns black (being the animation for her ult), there's an Elise cocoon inside her, which just completely disregards Evelynn. Evelynn and the cocoon meet at the end of Eve's E.

Is this supposed to be like this? That as long as she buffers her R, she's immune to cc?

Also, how bad is Elise E animation?