THE PLT OF AN SMA TOOK OFF IN THE WRONG DIRECTION CAUSING AN APCHING ACR TO GAR. THE RPTR DOES NOT RECALL IF THE RWY WAS SPECIFIED WHEN HE RECEIVED HIS CLRNC FOR TKOF.

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I REQUESTED A RWY 34L DEP; TFC PERMITTING; AND ADDED THAT I WOULD ACCEPT A DELAY IF REQUIRED; AS I WAS NBOUND. GND REPLIED THAT THERE WOULD BE A DELAY FOR WAKE TURB AND TO TAXI TO TXWY A8 VIA TXWY A; WHERE I COULD DEPART WITH 4000 FT REMAINING AND HOLD SHORT. I ACCEPTED; AS MY TKOF RUN WAS COMPUTED AT APPROX 1000 FT. I OBSERVED ANOTHER ACFT ON FINAL FOR RWY 16R; WHICH I JUDGED TO BE AN AIRLINER; INSIDE THE OM. I SWITCHED TO TWR AND ADVISED I WAS PREPARED FOR AN IMMEDIATE TKOF AND COULD MAKE AN IMMEDIATE L TURN WHEN AIRBORNE; TFC PERMITTING. I WAS CLRED FOR IMMEDIATE TKOF. AT THIS POINT I WAS CONVINCED THAT ALL THAT HAD TRANSPIRED SINCE MY INITIAL REQUEST FOR A N DEP HAD BEEN TO ACCOMMODATE MY REQUEST AND POS ME FOR A N DEP. I ACKNOWLEDGED TKOF CLRNC AND NOTED THE ACFT ON FINAL. I JUDGED THAT WITH MY PLANNED L TURN AFTER AIRBORNE THERE WOULD BE NO CONFLICT. SHORTLY AFTER BECOMING AIRBORNE THE TWR ADVISED I HAD NOT BEEN CLRED TO DEPART ON RWY 34L; BUT ON RWY 16R. I DO NOT RECALL THE TWR STATING RWY 16R OR RWY 34L WHEN ISSUING CLRNC FOR IMMEDIATE TKOF. NOR AM I SURE IF I FOLLOWED MY USUAL PRACTICE OF READING BACK THE CLRED RWY. AFTER BECOMING AIRBORNE AND ON A HDG OF APPROX 320 DEGS; I HEARD A CALL 'GOING AROUND.' STILL ON A SHORT FINAL THE AIRLINER HAD ROTATED TO A CLB ATTITUDE. I DO NOT KNOW IF THE TWR CALLED FOR THE GAR OR IF THE CAPT DID. FROM MY PERSPECTIVE I DON'T THINK THAT A GAR WAS NECESSARY DUE TO A CONFLICT. HOWEVER; I UNDERSTAND THE TWR'S CONCERN SEEING AN AIRPLANE (MINE) DEPARTING IN THE OPPOSITE DIRECTION THAN THAT WHICH THE TWR HAD ANTICIPATED. I THINK THIS INCIDENT IS AN EXAMPLE OF AN UNINTENDED OUTCOME WHEN A MINDSET (MINE) WAS ALLOWED TO DEVELOP AS A RESULT OF LESS THAN CONCISE COMS. I DO NOT RECALL ANY REF TO RWY 16R AFTER MY INITIAL TAXI CLRNC. MY SUBSEQUENT REQUEST FOR RWY 34L AND THE REVISED TAXI CLRNC TO AN INTXN HOLD SHORT POINT WAS PERCEIVED BY ME AS AN INDICATION THAT I WAS BEING POSITIONED FOR A DEP IN THE REQUESTED DIRECTION. WHEN I READ BACK THE REVISED TAXI RTE TO HOLD SHORT OF RWY 34L; WITHOUT COMMENT BY GND CTL; MY BELIEF WAS REINFORCED THAT I WOULD BE CLRED TO DEPART ON RWY 34L. THUS; WHEN SWITCHING TO TWR AND ADVISING READY FOR IMMEDIATE TKOF; AND REQUESTING A L TURN; I WAS CLRED FOR IMMEDIATE TKOF. THE LNDG TFC WAS A FACTOR; BUT WITH MY PLANNED L TURN; NOT A CONFLICT OR POTENTIAL NEAR MISS SIT.