First of all, $2.5M is hardly chump change, even for a billionaire. It's pretty hard to view a $2.5M investment in a company as bad thing.

Second of all, I think he did buy all of the shares available. I'm pretty sure the offering was reduced from $4M to $2.5M by the company, not Ernesto. The company didn't need the full amount so they reduced it in order to limit dilution. If you look at the old press release, it says "up to $4M".