Originally Posted by flyingcrooked

That's not really what I was asking. I assumed you wouldn't get the greater level of compensation. What I was wondering is whether there is any issue claiming for the lower compensation, given that it was, in a sense, a voluntarily flight change. No, no issue. AC had a flight disruption (assuming airline controllable) and you were delayed more than three hours. Of course, it was prompted by the cancellation, but I don't know what kind of info AC tracks. Distinguish between:

Case 1: Six days prior to departure, AC cancels my flight and I'm automatically rebooked to arrive 24 hrs later. I hate that, so call them and get it changed to a routing where I only arrive 4 hrs later than originally planned. If it was airline controllable and less than 14 days notice you can claim APPR cash compensation. In this case you can still claim $400 cash for a 3-6hr delay.
Case 2: Six days prior to departure, AC cancels my flight and I'm automatically rebooked to arrive 24 hrs later. I'm fine with that, but then the next day my boss calls and tells me I need to get home for an important meeting. I call in and move to a flight that only gets me in 4 hrs later than I was originally scheduled to arrive. Because of the cancellation, the agent doesn't even bother to check whether the revised flight costs more or less, and as I book latitude fares there is no change fee anyway. Again, if it was airline controllable and since it is less than 14 days notice, and you arrive 4hrs later you can claim $400 cash for a 3-6hr delay. The fact that the agent doesn't charge you is irrelevant. Theoretically the airline has to get you to your destination as soon as possible. If the system auto rebooks you for 24hrs later and you find a new flight that is sooner the airline is obligated to change it to that flight if asked, so it doesn't count as a voluntary change and that is why there is no additional fare difference to collect (no change fee either if you weren't on a Latitude fare).

I guess AC doesn't see the extra information that distinguishes the cases, so is the idea that so long as an agent rebooks you under a 'flight cancelled' type of situation, you're entitled to the lesser of (i) the compensation you're due based on your actual arrival time, or (ii) the compensation you're due based on what they originally proposed? Correct.

Here's a different case that gets at a similar question: AC cancels my flight and rebooks me 10 hrs later. There are options that get me in only 4 hrs later, but for some reason AC doesn't book me on those. I use the self-service online system to select a routing that gets me home 24 hrs later, out of personal preference. After the flight, I file a claim for compensation. Does AC (i) give me compensation for a 10 hr delay, or (ii) give me compensation for a 4 hr delay, or (iii) gives me nothing? Assuming it was airline controllable, you get the $1,000 cash for a controllable delay that has you getting to your destination more than 9hrs late on the original rebooking. The fact that you say there are earlier options may be because availability is rapidly changing in real-time. Don't forget that when a flight that has ~400 people cancel availability will be changing by the second as people get rebooked and change their rebooking. Anyways, so if you saw a flight that was only going to be 4hrs late and took it, then you only get $400 because now your actual arrival delay is between 3-6 hours late. So it is up to you if getting to your destination is more important than the money you can collect (e.g.: do you want to get where your going 4hrs late and get $400 or do you want to get where you are going 10hrs late and get $1,000? At that point the ball is in your court, but if you wait too long to decide the earlier 4hr delay option may not be available if others beat you to it. Remember, not everyone cares about the $600 difference depending on their reason for travel). For the second part, if you then chose to not take the 10hr delay and take the 24hr delay you still are delayed more than 9hrs so it doesn't matter, you still get the $1,000.

In this case I'm wondering if the compensation folks can see that AC wanted to/tried to rebook me for 10 hrs later, and would base compensation off of that. Everytime you are confirmed on a flight is recorded with a timestamp, so yes, the Customer Relations Representative can see what you were booked for and what was changed along the way.