Hrm, apologies. I was at work and didn't have my Nexus on me. With the back button description I was mixing up its behaviour with the other back button (the one at the top left with the 'back' arrow). That's the one that dumps you out of your search results and back to the main category. I'm not sure if it's because I'm primarily an iOS user that I expect the '<' indicator next to it to mean "go back to the last thing you looked at".

The swiping thing was referring to the category pop-out in the main sections (Apps etc) which makes it feel like it should do something else. In retrospect I probably should have waited until I had gotten home and double checked whether what I remembered was correct before commenting. Having a flip through it, the store is less awful than it was last time I paid it any serious attention - having a decent stable of usable apps I haven't had much cause to go looking for new stuff lately.