No, the point is that the differences between two texts don't tell us anything in either direction. Plagiarists can write 99% of their essay themselves. You need to look at the similarities—however great or small—to determine whether or not there is evidence of dependence.

Many biographies in antiquity were written explicitly to correct their predecessors.

Even more proximately, the Gospel of Thomas was written with knowledge of the Synoptics to deliver an image of Jesus radically different from its sources.

Wow! What manuscript is this?

There's a "navel gazing" joke here, but I'm too sleep deprived to find it.

We've all been there.

Just finished this today. A delightful read.

I'd disagree with Mark more often if only he had worse opinions.

Loved this thread! What a cool little piece of the discipline's history.