To be fair, the guys that work in the CUU office are regular working stiffs like you and me. They're probably not sitting on a boatload of cash and already have so many shares that they're essentially "all in" already. As a friend in the industry once explained to me re insider selling and such - these people are real people like you and me. Their kids may need braces, they have mortgage payments
David is making these buys as an attempt to signal the market pure and simple because picking up 5K shares isn't going to change much in terms of where he nets out on this deal when he's already sitting on 12.5 million. Ernesto probably knows he's going to be asked to fill a PP in the coming weeks so buying at the market makes less sense for him.