The volume at the time of writing is 2.6 million. 1 million is...

The volume at the time of writing is 2.6 million. 1 million is therefore quite a hefty amount to 'drip feed' into the daily trading, especially when you consider other sellers as well. If there was truly the demand that you state for this stock, there wouldn't currently be 1 million sat on the sell side at 11c.

The person in question might have been able to get a slightly better deal for some of his shares (certainly not the entire package though) had he waited. But there's plenty of big deals on the AIM that could apply to every day. You don't have possession of all the facts and so cannot make the assertion that there is market manipulation. Maybe the seller saw another stock he wanted to buy, but believed he had to move quick? Maybe they're so rich they don't even care? Maybe they're in trouble with a crime gang and need the money immediately to pay them off? Who knows. There's plenty of plausible scenarios that explain a large seller.

Or the guy in question is just stupid. But stupidity isn't market manipulation- if it was, everyone buying RMP at 20p+ would be under investigation by the FSA. ;)