I've just tested this a few times. My very first try, I locked MC up and it wouldn't respond. This happens every now and then on the Mac version of MC; not often at all, but I've seen this kind of lock up happen before.
My next trials all worked as I expected. I pulled the playback slider to various places, including the very beginning of the track. When I pressed play, it played from that spot.
Now, I *do* know one way to make this fail. There is a "point of no return" on each song with MC. It's something like 8 to 15 seconds from the end of the song. Once MC reaches this "point of no return", it will not rewind at all in that song, or skip backwards. It has loaded the next track and it will play that next track before you can do anything else (with the current track).
Indeed, if I let it get to within about 8 seconds of the end, press pause, pull back the slider, and then press play, MC happily ignores me, skips back to where it was, plays 8 seconds of the end of the song and continues to the next. That's the only way I know to emulate the behavior you've described.
Brian.