I understand that as a feeling, but I can't logically justify it. What reason did he have to trust in the system to treat him fairly? The rightness of the programs he exposed, and our right to know about them, don't depend on whether he decided to martyr himself.

Why is that relevant? Is he a whistleblower or not is the question. Whether he gets pardoned from a jail cell or Russia makes no difference. Avoiding a trial isn't the central issue.