My Attempt against Debasing Demon

Schaffer’s argument:

1) (1) Knowledge requires the production of belief properly based on the evidence.

2) (2) Necessarily, for all beliefs, they can be produced improperly based on the evidence, via guessing or wishful thinking.

3) (3) Necessarily, for all improperly formed beliefs, it is always possible for them to seem later as if one had produced the belief properly based on the evidence.

4) (4) If (1)-(3), then it is impossible to distinguish cases of knowledge from cases of non-knowledge.

5) (5) So, it is impossible to distinguish cases of knowledge from cases of non-knowledge.

My argument denying (3):

6) (6) It is not always possible for improperly formed beliefs to seem later as if one had produced the belief properly.

7) (7) If (6), then it is sometimes possible to distinguish cases of knowledge from non-knowledge.

8) (8) So, it is sometimes possible to distinguish cases of knowledge from non-knowledge.