LONDON (Reuters) – The former deputy Governor of the Bank of England said he was "astounded" the U.S. government let Lehman Brothers go under, and that the bank's collapse marked a clear moment when people lost confidence in the markets. Sir John Gieve said in an interview with Sky News he had fully expected U.S. authorities to step in this time last year to rescue the stricken investment bank, as it had done earlier with peer Bear Stearns. The Federal Reserve put up $29 billion in March 2008 to underwrite JP Morgan Chase's (JPM.N) rescue of Bear Stearns, and was...