Possible Clues:

• Serious lapse
• Pride or greed, e.g. (NL Central)
• Birdhouse opening, perhaps
• Serious lapse for a Missouri baseball player?
• Major transgression
• NFLer's iniquity?
• Ethical no-no in St. Louis?
• Bird boo-boo?
• Missouri ballplayer's connection?
• Lust or gluttony, e.g