In his [autobiography][1] von Karman has a whole chapter (or two) dedicated to justifying why deporting Tsien just based on suspicion was a bad decision.
[1]: http://www.amazon.com/The-Wind-Beyond-Theodore-Pathfinder/dp...
[1]: http://www.amazon.com/The-Wind-Beyond-Theodore-Pathfinder/dp...
"The elderly Qian was able to watch China's first manned space mission on television from his hospital bed." http://en.wikipedia.org/wiki/Qian_Xuesen
Whatever the politics, he was recognized by his peers as being a genius, a great rocket scientist, and that will be his legacy.