pran, on 2017-September-26, 06:30, said:
Impossible to say without knowing all four hands.
But failure to alert is by definition (and law) misinformation, and as it is too late for East to change his last call the Director's ruling to play on is correct.
 
Too late for E, but W should have been offered a chance
17D The  auction  period  ends  when,  subsequent  to  the 
end  of  the  auction  as  in  Law  22A,  either  defender 
faces an opening lead.
21B 1. (a)
Until the end of the auction period (see Law 17D) and provided that his partner has not 
subsequently  called,  a  player  may  change  a  call 
without  other  rectification  for  his  side  when  the 
Director judges that the decision to make the call could well have been influenced by misinformation given to the player by an opponent. 
Failure  to  alert  promptly  where  an alert  is  required  by  the  Regulating  Authority  is deemed misinformation. 
Before the opening lead would seem to be early enough unless ACBL doesn't use the new laws unadjusted.
Raises a question or two.
W exercises the right to change his bid, is his pass cancelled ? has he now called ? If it is cancelled, can E now say his partner hasn't called and have his bid back ?
Also what's the UI situation of W changing his call knowing E summoned the director and may have wanted to bid.