As chairman of the Association of Teachers and Lecturers' legal defence committee, I would like to give your writer some "non-anecdotal" evidence. Most of the cases dealt with on behalf of our members are for personal injury, and these cases often take years to resolve and cost thousands of pounds.
Your writer must have read of the recent successful cases brought by ATL on behalf of members badly advised about pensions, and few teachers have the savings necessary to take on financial giants. Recently, a teacher used a so-called "no win, no fee" firm for an industrial tribunal, and was presented with a bill for more than Pounds 15,000, and this did not include the LEA's costs!
The only teachers who do not need to insure their career by joining a union are those who have such blind faith in their life-long good fortune that they do not insure their house or its contents!
If your writer is concerned about any conflict of interest between union officials and headteachers, then look no further than the ATL, which is the only union that excludes headteachers from membership.
National executive, Association of Teacher and Lecturers
7 Northumberland Street