Another bug in SVN 10389: I happen to have completed National Science Foundation wonder (gives 1 free tech) and researched Liberalism tech (gives 1 free tech), so I should have received 2 free technologies at the end of the turn. The pop up did appear twice and let me choose a free tech. However, only the first choice remained. The second choice (which I selected in the pop up in conjunction with completing National Science Foundation) did not stick. So, apparently there cannot be 2 free technologies chosen (due to different triggers) at the end of the same turn.