The Theoretical Error S(X,Y,Z) has to do with the computed 3D position of the GCP. It does not take at all into account what is the Initial (input) position of the GCP. It indicates:
- How good was the relative reconstruction.
- If the point needs to be marked on more images.
For more information: What is the Theoretical Error S(X,Y,Z) of a computed 3D point?.
The Error to GCP Initial Position gives the difference between the initial and computed GCP position in each direction (X,Y,Z) and indicates problems with the georeference.
So a point can have high Error to GCP Initial Position and small Theoretical Error S(X,Y,Z). In this case, the point has been marked correctly on the images (the same point was marked on all images), the relative reconstruction is probably correct, but there is an error with the georeference. The input coordinates of the GCPs should be checked.