I thought the higher levels of the AI were just bonuses to well everything, not free techs and even then it seems excessive, ...
It could be they were following the enlightened path and got some help from artifacts too.
The difficulty settings aren't finalized yet. Right now there are no strong AI functions that the higher difficulties can draw upon (such as Gal Civ 2, most of what higher difficulty settings were doing was allowing the AI to have access to advanced functions (strategies/tactics/management/etc)). In GC3 none of those functions yet exist, as the base game hasn't been finalized yet - so all the good AI stuff hasn't been written yet.
When the game finally ships - I doubt that the AI will get free stuff. But with just the base AI in the beta, the only way to make the AI harder is just to give it free shit...
As you pointed out, some of what you saw may have been somewhat luck-based. The Alterans starting in a location that was awesome for research and just starting down that path 100% from the get-go. But I agree, the pace seems fast...
cheers,
-tid242