Henry London would not have been the Color Bearer at Gettysburg as he enlisted much later.
This story must have come from his history of the 32nd.

Henry Armand London
Co. I 32nd NC Inf. enlisted age 18
born 3/1/1846
died 1/19/1918 in Pittsboro, NC
enlisted January 1, 1865 at Pittsboro, N. C., detailed on extra duty as Courier at Division HQ

………………..

Confederate Veteran Magazine V 26, p.116

The Last Roll
Henry Armand London.

Editor Chatham Record 1878 for 40 years

“His contributions to literature bearing on the war period are not second in importance to those of any other man in the State. Among such contributions his "History of the 32d Regiment" stands out prominent in Clark's ‘Regimental Histories.’”

https://ia800203.us.archive.org/32/items/confederateveter26conf/confederateveter26conf.pdf