EVASIVE ACTION GAR DUE TO CLOSE INTERVAL ON DEPARTING ACFT.

Narrative

TWR MISJUDGED MY APCH SPD AND CLRED ANOTHER ACFT FOR TKOF. ACFT WAS SLOW TO DEPART AND A GAR WAS NECESSARY. AS I EXECUTED THE GAR; THE FO BECAME ALMOST USELESS. THE FLAPS HAD BEEN RETRACTED; GEAR UP AND TWR HANDED US OFF TO DEP WITH AN INITIAL HDG AND ALT. FO WAS NOT RESPONDING TO TWR; NOR DID HE SEEM TO BE RESPONDING TO MY REQUESTS THAT HE RESPOND TO TWR. AS I WAS TRYING TO GET FO BACK IN THE LOOP; THE COCKPIT DOOR OPENED AND THE FIRST FLT ATTENDANT WALKED IN AND SAID 'WOW; THIS IS EXCITING; WHAT'S GOING ON?' I'M AFRAID I LOST SOME OF MY COMPOSURE AS I YELLED AT HIM TO GET OUT OF THE COCKPIT; AND THAT HE WASN'T PERMITTED HERE DURING TKOF AND LNDG. HE RETREATED. AS WE LEVELED OFF; I MANAGED TO GET THE FO BACK INVOLVED IN THE PROGRESS OF THE FLT. A NORMAL APCH AND LNDG WERE MADE. FO LATER SAID HE WAS SO INVOLVED IN WATCHING THE DEP ACFT THAT HE BECAME OBLIVIOUS TO OUR SIT. I HAVE NO REAL IDEA WHY 2 PROFESSIONALS; THE FO AND FLT ATTENDANT; SEEMINGLY WENT BRAIN DEAD AT THE SAME TIME. I WAS EXTREMELY BUSY AS A SINGLE PLT FOR SOME TIME AND I NEVER EXPECTED A FLT ATTENDANT TO COME INTO THE COCKPIT DURING A GAR.