Is this treatment really no big deal?

According to the March 21,2017 issue of Hyperallergic, on Saturday March 18th, a man with a screwdriver damaged a Gainsborough painting in the National Gallery London (“Thomas Gainsborough Painting Gauged at London’s National Gallery” by Benjamin Sutton). The National Gallery spokesperson is quoted as saying, ““The painting was removed from display and examined by the Gallery’s conservators. The process of consolidating the pigment layers in the areas affected by the scratches began immediately. The preliminary reports suggest that the damage can be repaired relatively easily and the picture should be back on the wall shortly.” I understand the desire of the institution to calm the public and play down the seriousness of such an incident. However, even minor conservation work requires skill and knowledge. If this treatment was no big deal, why couldn’t anyone who fancied himself or herself a restorer have done it and why do conservators work so hard to separate themselves from untrained restorers.