An A320 Captain continued the takeoff from a high altitude airport despite an ECAM HOT BRAKES warning received below 80K.

Narrative

During the cockpit setup I observed the right brake temps over 450 degrees with the left wheels in the mid 300s. By the time we pushed back; the right wheels were in the mid 200s and the left wheels were in the mid-100s. Taxi clearance was received for Runway 25; a generally downhill route from the gate. Because of the temperature split between the right and left trucks; I elected to use minimal braking with the left gear only; allowing the right truck to cool further on the way to the runway. We had a short delay in receiving final weights necessitating a period of time with the parking brake set just prior to beginning the takeoff roll. During takeoff at approximately 70 KIAS the Hot Brakes ECAM and Caution sounded indicating that one of the left wheels was over 300 degrees. This did not make sense; as just prior to taking the runway both brake temps on the left side were well below 200 degrees. The First Officer was pilot flying and I advised him to continue the takeoff. The power was never reduced; nor were the brakes applied. As a precaution; once safely airborne we completed the 'Hot Brakes' ECAM procedure. Point one: Prior to my flight day; I read through the maintenance records of this aircraft and one other. When seeing the above ECAM during takeoff; I incorrectly remembered the maintenance history indicating the exact same brake temperature event during a takeoff by another crew. The mistake: This event occurred in the other aircraft; not ours. Point two: While the rapid rise in left wheel temps during the start of the takeoff roll did not seem to be likely; or even possible; I feel that I should have relied upon the takeoff safety briefing (as given by me) and aborted the takeoff in the low-speed regime. Point three: Contract Maintenance was called out to check the left wheel assembly and a loose connection was found; and the brake temperature indicating system was deferred.