I had a look at the actual record in Scotland's People and Margaret Hunter, was the relict (widow) of Francis Finlayson when she married William Tough. There is a record of a Margaret Huntar marrying Francis Finlayson on 3 December 1703 at Kilmarnock, which is probably this first marriage.
Given Scottish women tended not to take their husband's name, explains why she is married for the second time still as Hunter, but whoever transcribed the record for the Scotland, Select Marriages database, presumably thought they should include both names.