Based on this excerpt, what can you conclude about Confederate spy Henry Harrison?

While Longstreet was holding this position, a scout, more properly a spy, was placed at his service by the War Department. His time seemed to be passed about equally within our lines and the enemy's. Harrison (such was his name) always brought us true information. There was always confirmation of his reports afterwards.
While one is always suspicious that such spies give away as much as they bring and may be in the pay of both sides, it was difficult to be sure of this in Harrison's case. He went everywhere, even through Stanton's War Office at Washington itself, and brought in much. We never discovered that he sold anything against us; besides, we verified his account of himself as coming from Mississippi.
Adapted from G. Moxley Sorrel, Recollections of a Confederate Staff Officer