At the end of The Defector (orig.: L'espion) Peter Heinzmann meets up with Prof. Bower and Agent Adams in West Germany after he defected (more or less due to his experiences in Bower's case). Yet we know that he actually was sent there against his will by the Stasi (after having been deliberately shot multiple times for better alibi) to get further friends with Bower and try to turn him over to the East yet again. But when leaving them as pedestrian he gets into a street accident and is hit by a truck. He dies in Bower's arms saying something like
Maybe it's better this way.
While this seems to be alluding to the neverending circle of mistrust, defection an anti-defection they were trapped in and which is finally broken by his death, it is still unclear to me if he actually killed himself by running into that truck on purpose or if this really was just an accident. Maybe this is intentionally left open for interpretation, but maybe there is a definite answer I missed from the movie or it is further explained in the source novel.
And in addition to that, if he really killed himself, I wonder why he did so, given that he had alternatives. In the end he was sent into the West as a free man and had no motivation to participate in the Stasi's plans. He could just have explained the situation to the CIA (or not said anything at all about it) and switch from a pretended defection to a real defection instead of commiting suicide.