[Gameplay]Vi ult acting as cleanse?

"While i was playing Veigar i stunned Vi with my e but after being stunned she ulted me while the stun was still in place. The description of the ability says she cant be stopped when she ults. Is this because she ulted me before being stunned and then while stunned i ended up in range?"

above the line is repost from my discussion in gameplay i saw the line that represents the stuns duration appear over her head before i was ulted