You're right con-pilot, it is highly improbable that we'll ever know what really happened.
Of course the Venezuelans are not alone. The Peruvians, Bolivians, Ecuadorians and Colombians have been shooting down light aircraft drug runners for years. It's a high risk business. What I found most unusual about this one is that the intercepted aircraft was a business jet. That's not the norm.
Not to say that bizjets don't carry drugs but usually they fly around with (purchased) permits and flight plans, not invading airspace unidentified.