B737 CAPT DID NOT HAVE SUFFICIENT TIME TO PROVIDE TWR CTLR WITH A FULL READBACK DURING LNDG ROLL OF HOLD SHORT INSTRUCTIONS.

Narrative

TAXI AFTER LAND DURING ROLLOUT ON RWY 09R AT MIA; JUST PRIOR TO TXWY T3; TWR ADVISED US TO CONTINUE TAXIING AND HOLD SHORT OF RWY 12. I KEYED THE MIKE AND RESPONDED AND THEN REALIZED THAT I QUICKLY NEEDED TO TAKE THE AIRPLANE FROM THE FO IN ORDER TO SAFELY EXIT THE RWY. THE FO WAS AN AGGRESSIVE STOPPER AND INSTEAD OF RELEASING THE AUTOBRAKES AND COMING OUT OF REVERSE -- TO QUICKLY EXIT AT THE NEXT HIGH SPD -- HE WORKED BRAKES AND REVERSE FAIRLY HARD TO MAKE THE VERY FIRST AVAILABLE EXIT. NOTHING WRONG WITH HIS TECHNIQUE; BUT I HAD TO SHORTEN MY RESPONSE TO TWR AND SAID 'WILCO' INSTEAD OF THE FULL READBACK OF HOLD SHORT INSTRUCTIONS. I IMMEDIATELY NEEDED BOTH HANDS TO SAFELY TAKE CTL OF THE AIRPLANE. IRONICALLY; I WAS ABOUT TO ASK THE FO TO GIVE A FULL READBACK WHEN THE CTLR PROMPTLY MADE ANOTHER CALL INFORMING US THAT A FULL READBACK IS REQUIRED. NEXT TIME I WON'T BE SO QUICK TO MAKE A RESPONSE WHEN AN EXCHANGE OF ACFT CTL IS IMMINENT. THIS DOES BRING UP THE WHOLE ISSUE OF RADIO COMS. BUSY FREQS; BLOCKED CALLS; CTLRS NEEDING INSTANT RESPONSES FROM FLTS; AND CREWS RARELY GETTING THE CHANCE TO CONFER AND CORRECT AN INCORRECT RESPONSE TO A CLRNC. I THINK IT'S AN AREA THAT NEEDS MORE ATTN.