South asked about 4♦ bid and got explanation that it is strong and natural. The explanation was incorrect - the actual agreement was that it was a two-suiter, diamonds and unknown major. South passed. West bid 4♥ meaning it as natural suggestion of contract (he held six to KQ), but East obviously interpreted it as pass-or-correct and bid his major. West, holding three spades and one diamond, passed. Before the opening lead East corrected the explanation. Contract went down three and South called TD claiming that with correct explanations he would double both 4♦ and 4♠. He also claimed that he did not think that 4♠ was natural (according to local regulations no bids above 3NT are alerted without screens) and did not ask because of fear of producing UI, since he did not want to double cue-bid.
TD ruled 4♠* -3
Do you agree?
P.S.: There is no allegation UI in the deal.