It's the usual canned response from Metro. My guess is the return of those CAF cars is at least a year off because the investigation is ongoing.
I was looking through YouTube some more and got a clearer video/sound of the Bombardier MITRAC motors that sound identical to the Rohrs. These are used in Madrid on CAF built cars. Only difference is the slight power down on deceleration.
3000 series train accelaration:
http://www.youtube.com/watch?v=mKDHUmWJy3Q
8000 series train deceleration:
http://www.youtube.com/watch?v=YXjIphqwNJI
Apparently CAF uses this traction package on the new Madrid trains and their new Rome line A trains that is traditionally supplied by Breda. Bombardier also uses this version in Shenzhen and Guangzhou on their Movia trains. These sound more like the Rohrs because these systems use overhead canternary and usually around 1500 volts compared to 600-750 on the version used in Washington.
Interestingly, the version of the MITRAC system used on the Washington Metro is used elsewhere too. It's used in Bucharest, and on the new 2009 tube stock for London. I will say it would be interesting if any of the new trains used the AdTranz/Bombardier propulsion used in the BART system lol. Anyways, now that I've gone off topic enough...
Gotta love Alstom. Every year on opening day of hunting season, it is a paid holiday!