My take on this is pretty much the same as UTR’s
I don’t believe Nadar’s intention was to be offensive or to interject race, but in the US in 2008 you simply can’t use a term like Uncle Tom without doing so, particularly when referring to the first black President-Elect of the US.
If you listen to the entire video clip, Nadar never backed down from the term at all, but he did explain exactly what he meant. A bit later in the clip he did substitute the term “toady” for Uncle Tom. It’s unfortunate that he did not choose “toady” initially.
I’m not defending his use of the term here. As stated, it’s unfortunate, but I don’t believe Nadar is racist.