Single vs Twin I'm not as smart as all the geniuses here.  

I think if I had ever had a low or high-side failure in a twin helicopter, I would have screwed the pooch.

We never had enough training on handling those different types of failures.  You only get one shot when one engine misbehaves.  You have to be right and you must act quickly.  Not being a genius, prolly would have simply treated the low engine as a failed engine.  If I got the coin toss right, I woulda been a hero.

I went 30 years accident-free and old-fashioned luck was part of that clean record.  And we never had enough training.  Of the two types of twins I flew (for 10 years) there was no simulator, therefore no real practice handling those emergencies.

That's my "problem" with twins.