[srmanuel]

The Israelis paid him off and he did join them in sabotaging the Egyptian rocket program up to that point.

[Marinario]

It might be also he had a change of heart It was not about money, as I read.

[Marinario]

Raviv and Melman speculate he may have wanted to ensure the Mossad would not kill him, that he was seeking atonement for his Nazi past, that he was attracted by the idea of once again engaging in secret missions or a combination of these factors