You can trade endless techs with other factions. If I research 2 endless techs and my other alliance member researches 1 (or I do all 3 etc), then they can be traded which counts towards the victory. Meaning you only need to get 3 between the members of an alliance and give them to others to win the game. This can be done with as many people as in your alliance. With 3 people, each person researches a tech (different to the others) then you just trade your tech with the other 2 and they do the same with you winning the game on the next turn since you now have 9 of 8 required. This could be fixed by either costing a ton of influence to do the trade or better yet, just remove the ability to trades endless techs.