That's pretty unlucky since most of the time stealing tech seems to be about 75% or better.
Inspired by Axident and a couple of SGs (Thief economy) my current game is all spys, all the time. I'm finding it a fun and different way to play. The constraints are to research only worker techs and alphabet. After that it's steal everything else.
I think if one wants to be the tech leader as a game goal, then spying is not really an option. One can't do both well.