{GAMEPLAY BUG} when Vi ult gp and gp presses w, gp flies in the air for a while

Soo basically its what i said in the title

When Vi presses R for gangplank just as Vi throws gp in the air and gp presses w then gp starts flying in the air for longer. its as if it was a yasuo ult

This happened to me in a game recently, also i seen it in a youtube video Link for youtube video. the bug is at 4:48 : https://www.youtube.com/watch?v=imP_8d2GHAY