Why does my Arduino switch Debounce routine bounce?

Why does the LED flash twice with one push and release of the button?

#include <Servo.h>

Servo Stop_servo;  // create servo object to control a servo

// Buttons with Pull-Ups are "backwards"
// Some DEFINEs to make reading code easier
#define PUSHED false
#define NOT_PUSHED true
#define WATCH_BUTTON true
#define IGNORE_BUTTON false

// Time to wait for bounce, in MICROsconds
const int buttonWaitInterval = 6000;
// Pins for LED and Button
const int LEDpin = 5;
const int BUTTONpin = 2;
float Minpos = 0;    // variable to store the servo position
float Maxpos = 255;  //greatest travel of servo

// Used to track how long between "bounces"
unsigned long previousMicros = 0;

// Used to track state of button (high or low)
boolean previousButtonState = NOT_PUSHED;

// Variable reporting de-bounced state.
boolean debouncedButtonState = NOT_PUSHED;

// Tracks if we are waiting for a "bounce" event
boolean bounceState = false;

// Nothing surprising here
void setup() {
  pinMode(LEDpin, OUTPUT);
  pinMode(BUTTONpin, INPUT_PULLUP);
  digitalWrite(LEDpin, LOW);
  Stop_servo.attach(3);  // attaches the servo on pin 3 to the servo object
  Stop_servo.write(0);

  Serial.begin(9600);
  Serial.println(F("Serial Initialized"));
}

void loop() {

  // This needs to be called periodically to
  // update the timers and button status
  updateButton();
  // This replaces: digitalRead(BUTTONpin);
  //digitalWrite(LEDpin, debouncedButtonState);
  if (debouncedButtonState == LOW) {
    digitalWrite(LEDpin, HIGH);
    delay(500);
    digitalWrite(LEDpin, LOW);
    delay(500);
    Stop_servo.write(255);
    delay(5000);
    Stop_servo.write(0);
    Serial.println(F("servo cycled"));
  }
}

// All of the magic happens here
void updateButton() {
  // We are waiting for any activity on the button
  if (bounceState == WATCH_BUTTON) {
    // Get and store current button state
    boolean currentButtonState = digitalRead(BUTTONpin);
    // Check to see if a transition has occured (and only one)
    if (previousButtonState != currentButtonState) {
      // A transition was detected, ignore the others for a while
      bounceState = IGNORE_BUTTON;
      // Store current time (start the clock)
      previousMicros = micros();
    }
    // Keep storing existing button state, if we're watching
    previousButtonState = currentButtonState;
  }
  // We are waiting for the buttonWaitInterval to elapse
  if (bounceState == IGNORE_BUTTON) {
    // Compare current value of micros to previously stored, enough time yet?
    unsigned long currentMicros = micros();
    if ((unsigned long)(currentMicros - previousMicros) >= buttonWaitInterval) {
      // Store the state of the button/pin to debouncedButtonState, which "reports"
      // the correct value. This allows for the code to handle active high or low inputs
      debouncedButtonState = digitalRead(BUTTONpin);
      // Go back to watching the button again.
      bounceState = WATCH_BUTTON;
    }
  }
}

I'm trying to use Baldengineer debounce code to read a button and take an action. Each press of the button causes the LED to flash twice. The serial output reflects the routine running twice. 

I have failed in my code changes to get the result I hope. I have looked at Internet and have found no hints to help.