The rather stupid article that also read yesterday is typical of the sort of drivel that you find under the head "News" on websites such as Yahoo's - there's plenty of other such junk to be found on their front page, masquerading as "news".
I am guessing that Thomson comes out as the "most unsafe" UK airline as a result of the incident they had a few years ago, perhaps when they were Britannia when, if I recall correctly 757 G-BYAG ran off the runway at Girona when landing during a thunderstorm in 1999. I can't recall there were any fatalities, though the much more serious accident at LHR with the BA multiple engine failure must statistically - using the same rather silly yardstick, less safe than, say Monarch who haven't as I recall had any serious injury / fatal accidents through their entire history.