NMAC BTWN 2 C152'S ON DOWNWIND AT RVS; OK.

Narrative

MY STUDENT AND I WERE IN R CLOSED TFC FOR RWY 19R AT RVS. ON OUR 5TH CIRCUIT; AS WE TURNED DOWNWIND; ANOTHER AIRPLANE WAS ON A 45 DEG TO THE DOWNWIND (WE DID NOT KNOW THIS). MY STUDENT WAS FLYING ON DOWNWIND; AND I WAS ASKING HIM WHY HE WAS 100 FT LOW WHEN THE TWR CTLR ASKED IF WE HAD TFC AT 12 O'CLOCK POS. SAID 'NEGATIVE' AND WAS IMMEDIATELY UNEASY BECAUSE OF THE TONE OF THE CTLR'S VOICE; AND THE LACK OF DISTANCE INFO GIVEN BY THE CTLR. AT THAT POINT; ACFT Y SAID 'ACFT X IS NOW IN FRONT.' THE CTLR ASKED FOR CLARIFICATION FROM THE ACFT. THEY SAID A PLANE HAD JUST PASSED UNDERNEATH THEM. I LOOKED OUT THE BACK WINDOW AND SURE ENOUGH THERE WAS A C152 ABOUT 100 YARDS BEHIND US. AFTER SOME PROMPTING; THE CTLR ADMITTED FAULT; AND APOLOGIZED; WHAT BOTHERS ME THOUGH IS THE CTLR WAS HAVING A BAD DAY -- IT WAS NOT HER FIRST MISTAKE. SHE HAD CLRED US FOR THE WRONG RWY ON THE CIRCUIT BEFORE THIS ONE; AND I HAD CAUGHT HER MISTAKE; AND HAD ASKED IF WE WERE SUPPOSED TO SIDESTEP TO THE RWY SHE HAD NAMED (THE PARALLEL). THE CTLR HAVING A BAD DAY WAS THE MAIN CAUSE OF THIS INCIDENT. WHY SHE WAS WORKING; I DO NOT KNOW! CONTRIBUTING FACTORS WERE A HIGH NUMBER OF ACFT IN THE PATTERNS AT RVS; AND AN OVCST THAT MADE IT HARD FOR US TO SEE THE CESSNA ACFT ABOVE US; WHILE WE WERE CLBING TO PATTERN ALT. MORE SPACING AND BETTER TFC ALERTS; AND A LIMIT TO ACFT OPS AT RVS WOULD HELP PREVENT THESE INCIDENTS; BUT WOULD IMPACT EFFICIENCY AT RVS. MAYBE THE CTLR SHOULD HAVE EXCUSED HERSELF FROM WORK; LIKE I DO WHEN I'M NOT IN MY BEST SHAPE.