Weather at CGH:
It was raining, yes, but it was not a TS or +RA, more like a -RA or DZ for the past days. The runway was not contaminated; Sao Paulo tower does not allow ops at CGH with contaminated runway (there is a team from INFRAERO, the local airport manager, which measures the amount of water on the runway / standing water to determine the runway condition). So I find it hard to believe that the runway was contaminated. Due to the new surface, the runway gets slippery when wet, so extra caution is required. I personally think that my colleague had some other problem, such as loss of braking, flat tire, etc... All TAM pilots (or Brasilian airline pilots) are very experienced in landing at CGH, once it is a major airport, in terms of passenger volume and airline flights. I personally have 332 landing at CGH (all of them on B737 efis / NG or A319 / 320) in all kind of weather and never had a problem...never had a system failure also during the landing roll, so that's why I believe that he had some kind of severe failure, as mentioned before.
I consulted the Airbus MEL, and it says that no reversers are required for normal ops (only 2 rev required for ops at SDU – SBRJ airport) and the only operational item is to "not use the inop reverse during landing roll" - do not command rev. on that engine.