The fear was if they didn't race again after pitting they would have automatically lost.Merc blew it by not pitting Hamilton during the virtual safety car. Even if they lost position, they had the faster car.
I was referring to the earlier VSC when Giovinazzi I think it was broke down after one of the corners. But thinking about again even if Hamilton had changed to new tyres at that point, Max still probably would have passed him on a new set of soft tyres on the last lap.The fear was if they didn't race again after pitting they would have automatically lost.