Being eliminated early

I'll give you the background-

I was playing a world game, and was in South Korea. I allyed Japan ( I won't use any names) earlier, but due to him being a COMPLETE dead weight, I unallyed him after I had taken all of China and he just had Taiwan. The turn I unallied him, my cap was open because I transported my infantry out to make an important attack on beijing, and I didn't have the reinforcements to put infantry back in, but it was walled so I figured it was okay, and I had killed the other people in China so there was nobody to attack me anyways. The next turn, I find out that Japan took Seoul. Since we were at peace, there was no notification that I was going to die, so I figured when I warred him I'd have 2 turns to take it back, and even if it included that turn as him having my cap I could still take it back the turn that I declared war on him since the game rules specified 2 turns before elimination. I prepared my forces (which outnumbered his by a factor of more than 5) and declared war on him that turn, prepared to take Tokyo and Seoul in the same turn. The next turn however, there was a notice that Japan had taken my capital (which I figured), but it said that I was eliminated THAT turn, just one turn after he had taken my capital, even though he had taken it through his alliance, and we were at peace when he had it.

What makes me pissed the most is that I had done extremely well in the first 10 turns, I killed two Chinas, Indonesia, and scared India away, yet this level 0 took my cap while he was allied with me, and killed me without holding my cap the required amount of turns, with me having no chance of fighting back.

On a related note, I have observed a bug similar to this before: If during a capture the entire country game, two allies take different amounts of a seperate player's capital, and then the ally that didn't take the cap empties their cities so that the ally who did take the cap takes them, the player is eliminated immidiately, regardless of how many turns you are supposed to hold the country. (I accidentally did this a few days ago, but it wasn't as bad because he had lost almost all of his cities anyways, it just sped the ending up)

Could somebody please address both of these bugs? If used like in the first example, they can completely bullshit somebody out of a victory without the victim having a fighting chance.