For the better part of the past year, Occidental Petroleum Corp. OXY has looked like the blemish on Warren Buffett's otherwise bulletproof track record. With shares down 27% over the past 12 months and well below Buffett's average cost basis of $54.20, the Oracle of Omaha's massive$12 billion stake in the oil giant had critics wondering if this was one value bet that misfired.Chart created using Benzinga ProBut that skepticism may be premature. OXY has quietly rebounded nearly 9% over the past month and is ...