It's not a matter of different durations, but quite simply a matter of different things have been recorded.
It is possible that the same recording is shared between tracks of slightly different length. Different mastering, minuscule difference in playback speed, slightly different fade-ins and fade-outs, or even several seconds of silence left at the end of the track to separate it from the bonus materials that follow. It's all the same recording (same musicians at the same place, mixed by the same person).
It is also possible that different recordings share the same length! Just because they are 3:00 minutes long does not make two recording equals, of course.
So what matters is what is in the recording. Is it the same performance, from the same place, at the same time, the same result of work by the same people?
In the example you gave, it is two different people who recorded a live show at two different dates. Sure it's the same artist on stage, but that's the only common point. It is entirely possible that their performance was very different on those two days. Also, the crowd was inevitably different around the recorders.
Different recordings for sure.