I was off sick for 8 weeks at the start of last year, followed by 2 weeks of half days to get back into the rhythm of things. The day after I rang my boss to say my doctor had signed me off for a while I was given an appointment with our Occupational Health team, who 'vet' all long term sickness absences.
The way our sickness absence monitoring works is that you are restricted to a certain total of sick days in a rolling 12 month period, and no more than 3 sickness absences, self certified or doctor's notes, in the same period. If you breach this you are given 'special' interviews and your attendance is strictly monitored for up to 6 months. Most other Local Authorities I know of work similar schemes, so I suspect there is some 'exaggeration' in this story.