Insufficient bid mentioned by the player out of bidding turn, just before his partner bids...
South has made an insufficient bid, and West is touching the bidding box with intention to bid. Then East comes in, who mentions IB, West leaves his hand from bidding box, and TD is called.
South complains that East has no right to warn his partner, as West decides if he would accept his IB or not!
Maybe it it’s an easy case, if not in grey zone… Your ruling.