Ashutosh Jogalekar in The Curious Wavefunction:
Ironically it is the two most publicly known facts about Teller that are also probably not entirely accurate. Later in life he often complained that the public had exaggerated his roles in both the hydrogen bomb program and in the ousting of Oppenheimer, and this contention was largely true. In truth he deserved both less credit and less blame for his two major acts. Without Teller hydrogen bombs would still have been developed and without Teller Oppenheimer would still have been removed from his role as the government’s foremost scientific advisor.
The question that continues to dog historians and scientists is simple; why did Teller behave the way he did?
More here.