Going to Idealab's Pitchbook page: 202 investments, 135 'exits' (I think this is where you get your 65% number), but 65 of those 135 'exits' were bankruptcy.

I'm skeptical as well though willing to listen.

Which public resources? I didn't see any references cited.

It's pretty common in the startup space to exaggerate, but even a reference to a studio's own stats would at least be a good start.