Originally Posted by LovesIPA
The biggest risk is botulism poisoning, which can be fatal. I don't know how high the risk is, but personally, I wouldn't get that beer anywhere near my lips.
This is not perfect but my understanding is basically this:
Botulism sporification is what's harmful. Botulism bacteria require a completely oxygen-free environment for sporification. The slight bit of oxygen will keep the botulism bacteria from producing spores. Environments capable of fermentation are not good environments for the sporification of botulism due to competitive bacteria and oxygen. Canning is a great environment for botulism; an environment where the oxygen has been removed and all other bacteria have been killed. Botulism bacteria is present on many natural products we eat; honey being the most well known for containing high levels of botulism bacteria.
In regards to the OP question: I still very possible you had or have an infection or wild fermentation playing with your normal fermentation due to the long idle period. Keep an eye on your FG and see if it continues to creep lower.