Hazards of puncturing lithium-ion batteries?
Long term you're definitely going to die (of something).

You say you read the MSDS, but I didn't see a link. I looked at the MSDS of a Saft battery - nothing looks all that bad to me, just irritant and corrosive effects- nothing carcinogenic, no neurotoxins or other really bad stuff. The MSDS says for normal exposure to the innards (you didn't eat the battery or have stuff spray in your eye) "In severe cases obtain medical attention". You can judge whether this MSDS applies to you and if your case is "severe". 

I've cracked up Li-on batteries deliberately to see what kind of junk was being foisted off on us.. and I'm still okay (more or less). But then I used to play with blobs of mercury metal and melt &amp; pour lead in big open cauldrons (to make gamma ray shields for nuclear applications).