The 3S was initially not alerted. At East's turn to call he asked about 3S, was told it was "Natural and preemptive" (which, the eagle-eyed among you will note, is alertable in the EBU. It was meant as a splinter) and then passed. The auction continued to 5H doubled, which on the lead of a spade (to the hand that asked about 3S) rather than the normal club made 11 tricks. East/West then called the director to point out the possible unauthorised information from the explanation.
I'll post the ruling that was eventually reached later.