alea, according to available information, EDS did more than test it. They tried to hack it using name US and Russian expert hackers. 90% of the effort was directed toward the TAN. They finally gave up and asked for the location of 15-20 "secrets" in the E2. With that inside info they still could not break it.
BTW if anyone hacked an E2, they have hacked one PC and nothing more. The time versus reward ratio means it is not worth the effort like hacking a server for 100,000 credit card numbers.