When regulators liquidated Chicago Carriage Cab Corp.’s insurer, Ullico Casualty Co., and the Illinois Insurance Guaranty Fund, or IIGF, stepped in to defend a Cook County negligence case called “the Carrington action,” the first three reservation-of-rights letters that the guaranty fund sent to Chicago Cab were defective — despite sweeping statements about reserving all of the guaranty fund’s rights — because they failed to specify any particular policy defense. But despite those flaws …