ACR HVT OVERSHOT CROSSING ALT ON PROFILE DESCENT.

Narrative

OUR FLT WAS BEING VECTORED AROUND WX E OF BOULDER CITY VOR. AFTER CLRING THE WX WE REQUESTED A RADAR VECTOR TO CIVET INTXN--A HDG OF 215 DEGS WAS GIVEN AND LATER A HDG OF 225 DEGS WAS ASSIGNED. AT 132 DME LAX A DSCNT TO FL240 AT PLT'S DISCRETION WAS ASSIGNED; FOLLOWED BY 'BEGIN YOUR DSCNT.' THEN THE ALT FL220 WAS ASSIGNED. THE NEXT CLRNC WAS WHERE THE CONFUSION BEGAN. ON A HDG OF 215 OR 225 DEGS; WE WERE CLRED TO INTERCEPT LAX 25L LOC AND FLY IT INBND; MAINTAIN 14000' UNTIL ON THE LOC. THE LAX RWY 25L LOC WAS INTERCEPTED 65 DME LAX AT 14000'. WE WERE ASKED TO INCREASE AIRSPD FROM 280 KTS TO 300 KTS AND INCREASE AIRSPD AGAIN TO 320 KTS. I DO NOT RECALL BEING ASSIGNED A FINAL ALT OR BEING CLRED FOR THE PROFILE DSCNT. AT THE HIGH AIRSPD (320 KTS) AND THE ARNES INTXN RESTRICTIONS OF 10000' AND 250 KTS WERE GIVEN. THE FLT CREW UNDERSTOOD THE CLRNC TO MEAN 'CLRED DOWN TO 10000' WHEN ON THE LAX RWY 25L LOC.' IF AN ALT RESTRICTION OF 14000' UNTIL CIVET INTXN OR CLRED FOR THE PROFILE DSCNT MAINTAIN 14000' UNTIL CIVET WAS GIVEN; THIS INCIDENT WOULD NOT HAVE HAPPENED. AFTER PASSING APPROX 12500' OUR ALT WAS QUESTIONED AND WE WERE INSTRUCTED TO RETURN TO 14000'; CROSS CIVET AT 14000'; ARNES 10000'/250 KTS; FUELER 8000'/250 KTS; AND MAINTAIN 210 KTS TO DOWNE. I AM NOT PLACING BLAME ON ANYONE; BUT MY CREW AND I FELT THE CLRNC MEANT TO CONTINUE THE DSCNT TO 10000' ONCE ON THE 25L LOC. IT HAS BEEN MY POLICY; WHEN IN DOUBT ASK. IN THIS SITUATION WE FELT CENTER WANTED US TO CONTINUE OUR DSCNT ONCE ON THE LAX 25L LOC. SUPPLEMENTAL INFO FROM ACN 92908: THERE WAS NO MENTION OF XING CIVET AT 14000'. AT 14000' BOTH PLTS ASKED EACH OTHER ABOUT THE ALT AND BOTH THOUGHT WE WERE TO INTERCEPT THE LOC AT 14000' OR ABOVE AND THEN CONTINUE DOWN. IF THERE HAD BEEN A QUESTION ABOUT THE ALT WE WOULD HAVE QUESTIONED THE CTLR. WITH THE INCREASED AIRSPD AND THE UNDERSTANDING OF CONTINUING THE DSCNT ON THE LOC AND NO MENTION OF A CIVET ALT WE FELT THE CTLR WAS KEEPING OUR SPD UP FOR SEP (AS STATED EARLIER) AND EXPECTING US TO BE IN A POS TO LAND AT LAX. IN ORDER TO DO THIS IT LOOKED LIKE HE HAD SET US UP FOR THIS BY NOT MENTIONING A CIVET XING RESTRICTION SO WE COULD BE AT ARNES AT 10000'/250 KTS. A POS WE WOULD HAVE TO BE IN TO MAKE A SUCCESSFUL APCH AT LAX.