As acquittals are to be read for the least that they establish, not the most, the retrial on an attempted murder charge after an acquittal from a murder charge as to the second victim does not offend Double Jeopardy; logically there might have been reasons for the jury's decision other than the theory offered by the defendant.
In considering an Ineffective Assistance claim, it is the full course of representation that matters; the lack of impeachment on a specific point in the second trial was insufficient to, on its own, justify reversal.