I had about two fights where I first thought I was in multiplayer, but obviously was not (see MP thread about Alt-tabbing out and in again).

Here is the end of one:

After some chasing, I loose the 109. My Hurricane can no longer turn with it. It feels strange. I still have 100% throttle, am I hit? Right wing ok, left wing ok, I can not see any smoke from the engine. Is the engine sound very slightly
unusual, or am I just imagining things? My back is burning in anticipation of the deadly bullet that has to come, all of the furball is just behind me, slightly higher. But I have to fly straight, I am very low. I want to get away from the gaggle as fast as possible.
Noone seems to follow me, good! Is everything imagination? I have 190 kts, I think I slightly accelarated from a moment ago. I still cannot see any damage, I give up looking for it. Great, still no one following! As I am not sure I am in the right mission, I decide to set here down here regardless of what has happened. I slow her down, gear out, flaps full out, I am getting down to approach speed.
One last sight back, all seem to be occupied with each other in the furball. A look ahead. Good, a nice field. I make a nice landing, well, at least compared to other landings. As I get out I see the hits in the fuselage. I am almost glad that I have some hits, the CO would have been furious if I had landed for nothing

The other one:

Where are the pilots I know? All the planes around me are unknowns. Oh well. The furball is in front, slightly to the right. To the left is a single RAF fighter, entertaining 4 jerries! Well, lets give them a bit more attention! I fear I will be too late. But the 109 drivers are not very aggressive, they seem to mill about slightly above and slightly to the right of him, from my view point. Ok, 3 are still milling about, one is going in.
He is still too far away, but I need to scare him off *now*. A few shots and he breaks away at once. I do not even think I have hit him. I hope by going after him I have not been lead into the right spot for his comrades. The other Spitfire I am helping is tennis leader.
I fly a big circle so that I do not bleed energy too much and actually can gain a bit of height. Surprisingly, the other Mes are still not behind me. Two are still spectators to the fight, the third has now decided to attack. He shoots! At the same moment, tennis leader calls for help. Apart from being cautious, the jerry seems to be a bad shot. I have never seen so bad german pilots, maybe they use us for training? Well, lets turn this into a training of gowing down!
Tennis leader, hang on a few seconds! What is the hun manouvering about? It seems he does a scissors. Maybe he is better than I thought? Again, I try to ping the 109 from far away and again I get him to let go of the other Spit. I see no smoke, so I hope the jerry has not done much damage. I am getting nearer to him, I am still a bit faster, I can turn with any manouvre he does, for once I am in the better position. As the range closes to where I think I can damage or even kill him, I open fire again and again as he crosses my sight. The distance is decreasing and any small move by him is now a large angle difference from my point of view, so it gets harder and harder to keep him in the sight.
BANG! Excellent, that was a hit on him and I was so near that I heard it. I have to swerve to the right, so near am I. The others are behind me now, so I do not dare to try to slow down and get behind him again, I have to be content with that hit. After a few more turns, I am getting even lower, in a 45-60 degrees left bank. Suddenly, without any warning, there is a mighty *BAANNGG!!* Have I been hit?? It didn't sound so near. I did not know someone was directly in position to shoot at me. I am probably too low to bail! When I swerve my view to the left to look over my shoulder for the attacker, I still see the explosion on the ground. Was it a 109 or one of us? I do not know and have no time not care, I have to fight on, I can not help whoever is or rather was down there.