On some older jet fighters, pilots would use rudder to roll the aircraft. The problem with the ailerons was that in certain speed ranges the ailerons flap going down would not generated the same force as the flap going up so the roll would be unbalance. See Rudder roll
after seeing that link, how old of an aircraft are you referring to here? The "rudder roll" from the link still implies stick pressure (forward or back) I tested this theory this morning in the Texan and holding full right rudder with no stick input at an altitude of 3000 eventuates into lift of the left wing followed by a very slight slight nose up, then nose down with more left wing lift and eventual "spiral dive". usually a left stick pressure with full right rudder will hold the aircraft in a "crab walk" however the theory is as I tested this morning that a full rudder will end in a spiral dive and wing over whilst the nose is pointing toward the ground in a negative format.
as for a Jet as you have stated, I believe it will have the exact same result as you have stated "unbalanced" which requires stick input. the video has absolutely no stick input and there lies the issue.
Edit In my previous response to this a couple of posts back, I overlooked the IAS of the aircraft.
Whilst I write this, I have now just rewatched the video again, the poster is asking "where is the side slip"....side slip will not occur at 330IAS but more so around 150 or less IAS (which would still require left bank of the stick to keep the aircraft from rolling over). perhaps the author of the video has not taken into consideration that you can not "crab walk" an aircraft over 150IAS or what ever the rated IAS is in that rated jet aircraft unless an opposing force on the stick is applied to keep the aircraft level, then again......what would I know I've never flown a harrier before