That's not true at XJT. The CP doesn't call you. You get a nasty-gram about a week after the occurrence.
According to a union rep, no one has ever been fired for sick calls. At XJT, you have 3 sick calls allowed in a rolling 12 months and you get a nasty gram after the 4th. The 5th, 6th, and 7th will get you called in to the CPO for a meeting. My understanding is the rule basically stems from a lawsuit. A previous CP rarely enforced sick call abuse unless you were already a trouble maker. One guy was fired for many, many things and sick calls entered into the decision somehow. So they instituted a hard and fast rule across the board.