I started a new game as Altarian. Through 46 turns, with several re-loads, and at least one exit/hibernate/GC3/load, my technology tree consistently showed, in Age of Expansion:
- C3 Industrial Specialization
- C4 Advanced Construction
- C5 Construction Optimization/Optimized Manufacturing
- C6 Precision Manufacturing in Age of Expansion -- should be Age of War for Altarians
- C6 Practical Fusion, ibid. (which means "in the same place"
)
- C4 Xeno Mysticism
- C4 Institutional Research
- C5 Research Optimization
- C6 Research Centers
- C6 Research Coordination
I have no screenshot nor saved game from this state, because it never occurred to me that it was faulty. I completely overlooked that Altarian's racial trait of +20% research justifies pushing the C6 Research techs down into Age of Expansion, but not the C6 Manuf techs. In fact, I thought: cool, I can research up to C6 PM/PF to compensate for my lack of racial manuf bonus.
At least 3 times during the first 45 turns (still well within Age of Expansion), I deliberately set my tech to Practical Fusion before surveying an anomaly. So it was selectable.
This afternoon, I reloaded that game (to turn 46).
- The load time was exceptionally long: 2+ minutes(!!).
- Thereafter, the technology tree now shows C6 Precision Manufacturing and C6 Practical Fusion in Age of War (as expected for Altarian).
- I realized this because ... my Survey Ship is just about to survey another Artifact. So I do what I always do: Technology, Colonization ... and I cannot select Practical Fusion
==> yaay I found a bug 
I then started a new game as Altarian. On turn 0, its technology tree shows C6 PM/PF in Age of War (as expected).
So I have no proof. I'll scrutinize for future re-occurrences.