They are using the 2009-2010 lower end EliteBooks which means that is also likely that they are using a refurbished stock.

I'm pretty sure this is going to piss off both HP (for showing their logo clearly) and Apple and this is probably not going to last.

There are plenty of "hackintosh" guides out there, anyone who's capable of installing OSX on a non-Apple device has probably better hardware options out there.

And considering that this will never come with a pre-installed OS you aren't saving yourself any trouble buy buying it from them rather than buying the same hardware or newer from any other source.