I absolutely agree in that the patent system needs a major overhaul. Patents such as those mentioned impede research, thus slowing medical advancements and more. While I could definitely stand on a soap box regarding such problems (and have given that I'm in the bioinformatics field) I feel as though I would be preaching to the choir.

It seems that for a long time open source and artistic licenses flew under the radar of companies with patented software, being deemed insignificant and unworthy of the cost of litigation. However this has changed in recent years as companies are starting to feel the impact of such software efforts (The Monster Arrives: Software Patent Lawsuits Against Open Source Developers).

Given the question at hand - Can the author afterwards be pursued? I would think that it's possible but is it worthwhile for the company? It depends on the degree of "breakage", the magnitude of the problem (how prevalent is it? A handful of users or many users?), the amount of resources spent on troubleshooting, if the problem can be proven to be malicious or was it simply a programming mistake or an unforeseen consequence, etc...

As a developer I honestly don't lose sleep over a company coming after me -- not because my programming is always solid (trust me, it is not) but rather any problems I create truly are not intentional, rather a level of ignorance on my part in not understanding that my code is even capable of causing trouble. I seldom write code that interacts with patented software, but that is not to say that my code could not be used in conjunction with patented software that I have not tested or considered.

Futhermore, if they did come after me, they would really spend much more on the litigation than they could ever hope to get from me since I work in research!! :)