Fixing this error doesn’t generate new errors – it reveals new errors not previously detected. Many of these Single Sex Marriage errors were caused by file to gedcom conversions years ago which somehow reversed the husband and wife. By fixing the gender it often creates a new 303 Mother is male or 203 father is female.
Look at this profile of male William Henry Spangenberg (1887 - 1953) married to male Olive Estella (Farr). When you check their son William Henry Spangenberg, Olive is the father and William is the mother. By correcting the gender of Olive to female, you create a new error of George’s father being an female.
As far as the name being correct and incorrectly being flagged as an error, it certainly happens. But it is not going to create more errors than are fixed. I wouldn’t be surprised if this false positive error rate is less than 1%. It is up to the “Correction Officers” to be a little careful on any profile where the error isn’t obvious. If we are overly cautious about the rare case of a false positive error, WikiTree will never get cleaned up.