From the OpenSSL FAQ:

"Changes to the middle number are considered major releases and neither source nor binary compatibility is guaranteed."

Thus if everything magically continues to work it's hardly more than pure luck.

I would also think twice before downloading .deb files from questionable sources. I am not saying nieldk can not be trusted (in the other thread he says he understands the security concerns), but you don't even know with what options that .deb was built with.