Maybe it was a transcription error. After all, Ephesians and Colossians are among the Epistles (including Hebrews) whose authorship is disputed by some of the academics you dismiss as purely driven by an anti-Orthodox, in particular, or anti-Christian agenda in general.
If multiple authorship is possible, then transcription error is not impossible.
You aptly observe that in this case the theology is the same, i.e. unaffected by the addition (because the concepts contained in these verses are reinforced elsewhere), the very existence of such discrepancies shows human corruption of Scripture.
Neither of those books were disputed.
There is no transcription error, the blood is in Col.1:14.
If multiple authorship is possible, then transcription error is not impossible.
No one disputes the authorship that Paul wrote both books.
You aptly observe that in this case the theology is the same, i.e. unaffected by the addition (because the concepts contained in these verses are reinforced elsewhere), the very existence of such discrepancies shows human corruption of Scripture
No, without blood the verse is in error and there cannot be errors in the Bible text, if it is to be considered the Bible.