I am in the middle of playing on a large map and there are a few things that jumped out at me.

1)  Early on I built a city that apparently split one empire (Relias), they had cities to the north, and one city to the south (way south).  My influence cut off travel between the two, and the AI had sent, literally, 5 Pioneers to cross this area, one right after the other (maybe 2 squares between them).

2) Said AI's empire was much weaker than mine, but decided to go to war with me.  My guess is because all of their Pioneers kept getting blocked off.  Once he went to war, they all died.  With us at war, and him able to cross my territory, he sent more and more Pioneers to their death.

3) Once I got to his capital, and defeated him, he whisked away.  I was unaware that he had other cities, so I started scouring around.  I found 5 cities, all Tier 1, all with...a Hedge Grove.  /facepalm  The AI apparently went on the defensive, but WAY too early.  An AI should never build a Hedge Grove in a Tier 1 city.  Because of such, there were numerous resources that were unclaimed due to them being 1 square out of reach.  I took them over, demolished the Grove, added Hut, Profit.

There are still 5 more AI to decimate, if I run into any other oddities I'll post them here.  The plus side, knock on wood, I had zero crashes (though I didn't write down what turn I was on).