Perhaps our very attitude to statues is wrong. Everybody has their flaws, and sometimes those flaws are amplified e.g. by the time they are living in, the company they kept or the age that they were when those flaws became apparent (e.g. perhaps they changed in later life, or perhaps they died before they could change). If we're going to remove statues because of character flaws, perhaps we should not have statues at all.
Usually statues commemorate a good thing about somebody. If they have to be removed because it turns out that person also had flaws, there are going to be very few statues of real people - of angels. maybe.
If a statue celebrates, rather than commemorates/reminds, and if it celebrates a bad thing, e.g. slavery, then it's probably a good candidate for being removed or replaced with something more fitting for our time.