Kalista is confusing

I thought I was helping one farm with "kill securing" creeps but it turns out she wasn't getting the creeps nor was I. I also didn't have an option to decline her passive. I just stopped moving then was soulbound after a few seconds. I thought I'd have a chance to decline it.

She also makes riven's mobility look like kog's. I can't believe there is no cd on that passive.