Blitzcrank Q Not Functioning Properly

**Patch 6.4.16_02_22_17_11 ** Was playing a game with Blitzcrank and on two occasions hitting a lux and caitlyn with my Q the pull did not execute properly. On lux it did nothing but stun her and damage her without her moving. On Caitlyn in pulled her about 2/5ths the way and stopped pulling her inexplicably. As far as I can tell this is not due to other skill interactions, as neither was performing an action, having an action performed on them, or had any movement altering skills (Other than Blitz Q) used on them.