I don't know if it answers your question, but categorizing bugs to specific categories helps the dev determine what to prioritize.
Technical issues is not a bug but more on hardware/software IMO.
An example of exploitable bug is the alchemy trick in Skyrim. It renders all crafting as useless. There's also the leveling exploit in the beginning of the game. I don't know if it was patched since I only played it during the first week of release.
In short, bugs such as this makes the functionality of the game, as intended by the developers, obsolete.
If you played Dragon Commander during Beta, one bug was exploiting discount card + lots of money card. You could build an entire armada. I don't know if it was fixed since I've not played it after the Beta.
