Because it is a big company, as in absolutely massive, and because of China's disregard for IP, it could put a lot of resources(expertise, time and money) into unravelling the secret to the technology, after seeing it first hand having the plant setup and working in its own backyard.
The main point is that if they do discover the secret, they could employ it on there own and if little GER wants to take them to court, in a chinese court, it would be VERY VERY difficult.
To the point u did make, a takeover would not happen without the support of the Erdi group and the Israelis. Together Im sure they hold the controlling interest. They might accept an offer of a billion dollars. They may not.
But I believe the chinese prefer to figure it out for themselves and to be honest steal it, with little regard for western conventions and systems of justice.
GER Price at posting:
6.3¢ Sentiment: Buy Disclosure: Held