looks normal to me. 99,999,and 100 are all common numbers for the last page of doujins, mostly for the closing cover. but I don't doubt either that there could be more.
Wow, people, calm down. I tried to download another zip of the doujinshi and it had the same amount of files in it. I asked about it on a forum to make sure about it. I'll report back when I get a response.
God, shut the fuck up. The source is right there, and that's the whole doujinshi. If you don't think it is, stop complaining and GO LOOK for yourselves.