NS reserved their rights at the end of the auction because of the hesitation. West admitted she had been thinking.
Result: 5♦(E)=, NS -600
North called the TD at the end of play. East contended that any pause was no more than that required by the "stop" regulations, and that the STOP card had been removed as soon as the bid was made. NS did not dispute this. (The TD happens to know that this NS have scant regard for the correct "stop" procedure.)
When asked why he bid as he did, East said that as soon as 2♠ was opened he decided that he was going to pass initially, but would not sell out to 4♠.
How would you rule? If you decide there was no hesitation, say what you think of East's bidding if there had been a hesitation.

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.2♠...P...4♠..P(H)
..P....5♦...P...P
..P