I should have probably used "start" there instead of initiate to avoid confusion, sorry.
What I was trying to say was that it's possible that the benzoyl peroxide is a catalyst rather than a second initiator if it doesn't actually change during the process.
For example in school we used metal filings as a catalyst to break down hydrogen peroxide. The filings sped up the reaction but their structure didn't change, thus making them a catalyst.
I don't know if that is actually the case here, but I can't imagine Marian Newman would have listed it as a catalyst (if I'm not imagining things!) incorrectly and it would have gone unnoticed for so long if it actually wasn't a catalyst. Anyway, something for me to look into and learn from later! :green: