I would've been a little bit interested in knowing what was missing from the files, from the sound of it, something had happened to the main file where the plugin details are supposed to be stored.
Not to alarm you, but this could mean something had injected extra code into the start of the files, which is a common approach when trying to add malicious code to an unknowing system.
Or it could have been some anti-malware detection being a bit over-protective and removing the beginning of the details blocks.
Just thought it would be beneficial for you to know some of the potential scenarios/reasons causing the problems you had.