What is the authenticity of the the fatwa that permits fasting Friday alone if it coincides with a person's sole day off?

The Sheikh's intention regarding the dislike of singling out Friday for fasting might be based on the Prophet's (peace be upon him) saying: "Do not single out Friday night for prayer among the nights, nor single out Friday for fasting among the days, unless it coincides with a fast that one of you normally observes."

If fasting is difficult for a worker on days other than Friday, then there is no harm in fasting on this day, because he did not intend to single it out. The dislike is lifted by the slightest reason.