Nobody's smeared a load of vaseline or other grease over the front element have they? You've lost a lot of contrast and that would do it.
Were they using a lens hood? Light hitting the front element directly, say, from the sun somewhere near the frame will screw photos up, sometimes without additional ghosts.
The white balance is also pretty blue for the people, as they're in the shade. Different positioning to get better light would always have helped.
Oh, just to show what a bit of colour tweaking can do: (and this is lame, I'm not at my Mac so had to use the Gimp, which I have no idea in, I hope you don't mind the rehosting):
To me, after fiddling about, this looks like a touch of underexposure due to the sky, a poor whitebalance, and a dirty lens. I might be wrong on the last bit. The first two are things your friend needs to learn about if they're new - metering and colour. There are a number of books and websites which explain them, it's not an equipment thing.