With DAL you never know what you are going to get. About a year ago I was scheduled to fly SLC-ATL-AMS. The SLC-ATL flight was cancelled and they put me on a later trip which would have given me a :30 min connection to AMS. That flight was a little late. I ran like hell, caught the train to the Int'l terminal got to the gate just at scheduled departure time. The wouldn't let me on even though the jetway was still attached. I watched as it pulled away a few minutes later. I was "in the system" but it didn't matter. The agent said he never thought I'd make it. Had to wait two hours and go through LGW. I was not a happy camper.
Then last summer I was going SLC-CVG-LGW. We were ontime into CVG. #36 was loaded up and ready to go ontime as well when it was announced that they were going to wait for your illustrious flight 810 from LA as they had three connections. We sat for forty minutes, then the door closed and we left. No one got on. I overheard the agent say to the lead F/A that it turned out the "three connections" had missed the flight from LA and they had just realized it. Go figure.
On the return from that trip I was scheduled LGW-ATL-SLC. Long story short, all dressed up and ready to go in LGW - ontime - and the bird suddenly goes "hors de combat". We wait, strapped in for two hours. Bird suddenly revives, we leave, go to ATL. Naturally I now have eleven, count 'em, ELEVEN minutes to clear immigration and customs, get the ##$@*&!! train, change concourses and run 3/4th's the way down it to get my SLC flight.
I do.
Show up at the domestic gate, agent says "how the hell did you get here, ....we gave your seat away." I am livid, "well" I said, "I am here and I want it back. It was YOUR fault I almost didn't get here..." He looked at me as if I was from Mars, mumbled something, talked to the Red Coat, went on the plane, pulled a non-rev off, I got on and we left....ontime.
I don't know if it was the fact that I'm a Lifetime Medallion Million Miler, or that I had a full fare Business elite ticket that did it, but something worked.
Good Luck