Your managers were delusional antisocial personalities with very little experience in the field.

To run a demo in front of investors without ever having tried it even once and expect not to fail miserably! And then to blame anyone other than yourself when the inevitable happens.

I was in a similar position in a company where management would simply make up deadlines on the spot without even getting a spec for what was needed. The only saving grace was that they were quite patient when we were inevitably months behind, and that makes all the difference, because we just didn't take their dumb deadlines seriously, and everything was OK as long as we pretended it was possible. They were decent people overall, so being wildly stupid about deadlines isn't a big deal.

No, they also weren't successful, what makes you ask? 😄