There is absolutely a way that HG can offer a different price to...

There is absolutely a way that HG can offer a different price to the rest of us and they may be doing just that. They can buy on market at whatever price they like.
Once they reach 5% they have to declare their holding; but they can continue to buy on market at whatever price they like until they reach 20%.
If they go beyond this point they have to make a bid for the whole company and they have to offer the same price to every shareholder. This price can be different to what they have paid previously.