Sproul is right to distinguish the primary sources of divine knowledge (Scripture, nature) from the interpretations (theology, science). It’s a pretty basic and uncontroversial position, though on both the theological and the scientific side it’s actually quite uncommon to find people accepting that they’re disagreeing about human interpretations. Easier to say, “The Bible says…” or “the science is settled…”
The deepest problems come, though, from doubting the primary sources: on the side of nature, there have been a few who say that God has made nature deceptive to test us, but rather more who have said that because he wouldn’t do that, current science must be correct… quietly slipping human judgement into the “infallibility” area.
On the side of Scripture is the whole current dilution of Scriptural authority through the belief in human authorial error, which is quite different from asserting that no doctrine is infallible. It is true that all theology comes aboaut as a matter of human interpretation. But the claim of Scripture is that
“Above all, you must understand that no prophecy of Scripture came about bt the prophet’s own interpretation… but men spoke from God as they were carried along by the Holy Spirit.”
So to be a philosophical realist with regard to nature but a non-realist with regard to Scripture, or vice versa, is an assymetrical approach to truth.