I was amazed to watch trade after trade on WMN between 10:00 and...

I was amazed to watch trade after trade on WMN between 10:00 and 10:09am as the it got sold down from 6.6 to 5.1 c . And all before it was scheduled to become tradable - as @abn2609 helpfully reminds us in his pre market analysis :
___S PHASE (10:09:00 +- 15 seconds)

I watched in disbelief while my shares plummet 25% in value while I could do nothing about selling them even though someone on CHI-X obviously could . As I understand both exchanges are supposed to open in lockstep and I have seen off market exchanges of shares before , I don't understand what has happened here. I'd appreciate it if someone could enlighten me as to whether what looks like 'off market trading' behaviour is 'normal' and if so how some people/entities can do this but not us poor mugs trading from home ? .