ACR CLRED FOR TKOF; ROLLS. SIGHTS MLG NOT COMPLETELY OFF RWY. SHARP ROTATION TO AVOID MLG.

Narrative

WE WERE CLRED FOR TKOF ON 2L AT BNA. IT WAS NIGHT AND THE FAR END OF THE RWY WAS NOT DISCERNABLE. THERE WAS LIGHT RAIN FALLING AND WE WERE NEAR THE RWY LIMITED WT. DURING THE ROTATION THE FO DELIVERED SHARP ADVISORY AND DIRECTIVE COMMENTARY 'V1 ROTATE; PULL UP HE'S NOT OFF THE RWY.' I CORRECTLY INTERPRETED THIS TO MEAN THAT THE MLG THAT HAD LANDED BEFORE OUR TKOF AND HAD CLRED AT THE END TAXIWAY HAD STOPPED BEFORE COMPLETELY CLRING. HIS TAIL WAS HANGING OUT ON THE RWY. MY 2 DEG PER SECOND ROTATION WAS INCREASED AFTER BREAKING GND TO A PITCH OF 18 DEGS. ACFT NOSE UP UNTIL THE FO RPTED THAT WE HAD CLRED. MY CREW AND I FOLLOWED ALL INSTRUCTIONS ATC AND AIRLINES PRACTICES AND PROCS; INCLUDING VISUALLY CLRING THE TKOF PATH BEFORE INITIATING THE ACTUAL TKOF ROLL. HOWEVER; THIS TAIL STICKING OUT WAS NOT DISCERNABLE AT THE INITIATION OF TKOF. AT THE TIME OF ITS DISCOVERY WE WERE JUST ABOUT TO V1. A HIGH SPD ABORT WOULD HAVE BEEN A FAR GREATER RISK TO MY SHIP AND MY PAX THAN SIMPLY CONTINUING THE TKOF AND ROTATING AT A SLIGHTLY MORE RAPID THAN NORMAL RATE TO INSURE CLRNC. A SUBSEQUENT LNDG ACFT CONFIRMED THAT THE MLG WAS INDEED STILL PARTIALLY ON THE RWY.