The alarm bells are ringing for investors in Kohl's Corp. Earlier this month the retailer named its fourth CEO in less than three years, after the board fired chief executive Ashley Buchanan for directing business to an undisclosed romantic partner. Beyond the mess in the C-suite, the stock is down about 45% year-to-date as the company struggles to turn around declining sales in a sector that is an overall disaster. But the most glaring sign that something's amiss is the resignation of Kohl's board member Christine M. Day, a longtime retail executive who spent 20 years at Starbucks Corp. and was once the CEO of Lululemon. It's not the fact that she quit that should spark concerns, but how she went about it.