Ingenious Life and Death Puzzles, vol.1 binding error?

[Hushfield]

Hi, I was wondering whether anyone else owns a copy of Yang Yilun's Ingenious Life and Death, vol.1. I appear to be missing pages 12-15. Though the binding wasn't all that good, I'm pretty sure I haven't just lost them, and it looks like an error with printing or binding. As I couldn't find any information about this particular error on Sensei's Library, I was wondering whether any of you also noticed this problem.

[edit]:Nevermind, I found them, they're sandwhiched between later pages. Actually, it seems like most of the pages between 1-30 are just randomly inserted in the book:
1-2-3-4-5-6-7-8-9-10-11-16-17-18-19-12-13-14-15-24-25-26-27-20-21-22-23-28-29-30. Pretty weird.

Is this a one time freak accident, or does this thing happen more often with Yutopian Press books? If you compare the binding with Kiseido books, there's obviously a large quality difference there.

[Li Kao]

I think this is only a single binding error where two consecutive pieces of paper are in the wrong position. I assume
16 17 22 23
18 19 20 21
12-13 26 27
14 15 24 25
are the four affected pieces of paper. If you swap the lower two with the upper two you get:
12-13 26 27
14 15 24 25
16 17 22 23
18 19 20 21
which is the correct order. So it's definitely a binding error, but only a single and simple one. The order of the pages between 20 and 27 is a necessary consequence of moving pages 12-15 behind 19.