I'm amazed that, '"Some people got really bad rashes and this girl in my class had her lips bleeding..."' whilst simultaneously '"When the Sellotape started to come off she put more on."'
I wonder whether it stuck so tightly it ripped all the skin off when removed, or if it kept unpeeling...... 
And were the kids 'in on it' as an agreed joke/attempt to remind themselves not to talk, and did two children (quoted copiously in the article) act the drama lamas when they got home and play up to outraged mothers?
It's actually quite a cleverly worded article. It suggests one reading, yet is open to quite another.
Either way, I think the teacher was very foolish to do this, no matter whether it was 'red mist' or a jokey agreement with a bunch of chatty Year 6s.