It's all about the programs you use, really. Vim does support x selection buffers, and gvim should automatically take advantage of these (gvim --version should return +clipboard). In fedora (at least), the console vim with X support is called vimx (really wish it would replace the normal vim binary). With this I can just highlight and middle click to interact with the selection buffer. (I can even middle click in command mode without entering insert mode).

Now nearly all terminals have a clipboard handler (eg. for Gnome Terminal, ctrl+shift+v), but naturally this just blindly types the text. Does this mac person have the ability to do anything more than this? Maybe with X forwarding you could get a remove vim session with clipboard handlers to directly work with your clipboard.

The real problem is none of this is automatic, but the mac guy would need to go through most of these hoops as well, for the tools specified.