You're interpreting 'could have' as a possibility when it can also be interpreted as a statement of capability. - Evidence X, Y, Z points to a European origin

You're interpreting 'could have' as a possibility when it can also be interpreted as a statement of capability. - Evidence X, Y, Z points to a European origin for these discoveries. - How could Europeans have got to North Africa so long ago? - They could have done it by island hopping.