There has been a lot of confusion around content within tabs or "expand all" links. We covered it two different times and I thought I embed the latest John Mueller from Google had to say on this.
It is pretty fresh, from just a couple hours ago via a Google+ hangout. 50 minutes and 10 seconds into the video he said this is nothing new. They have always discounted hidden content within tabs or expand all links. If you want that content to rank well, then include it on its own page or include it outside of the hidden part of your page.
Here is the video, so you can watch it yourself:
Watch it yourself and take what you want from it.
Forum discussion at Google+.
