Hi, I think we should leave his birth date as 22.06.1850 as both his birth and death certificates had this date published. Perhaps there was an error on his grave stone?
The epitaph must be wrong. Both the illegitimate birth entry in HBM 484, as well as the birth entry with legitimation note in HBMa 1406, the marriage entry in HBMa 2671 and the death entry in HBMa 2671 clearly indicate June 22, 1850.