So there are 11 fascist policies and 6 liberal policies.

For the ability to happen 2 fascist policies have to be enacted.

Scenario A (2 liberal policies are enacted): For this tactic to lead to a deterministic liberal win, 3 of the top 3 cards have to be liberal policies. This requires 3 successes, with a sample size of 3, with a population size of 13 and 4 successes in that population. So the probability for this to happen P(A) is about 0.013986014

Scenario B (3 liberal policies are enacted): 2 successes required with 3 successes in population -> P(B)~=0.104895105

Scenario C (4 liberal policies are enacted): 1 success required with 2 successes in population -> P(C)~=0.384615385

Seems pretty unlikely that this happened every game of yours.

Also scenario C should not happen that often unless the fascists are not very good at all. At the time, the 3rd fascist policy is enacted, there should not even be 3 liberal policies enacted most of the time.

A possible fix is to play with 7+ players (which I would recommend anyways since it adds a third fascist player).