grub written over lvm partition

I was given an ubuntu desktop which has an interesting problem. It has
only one HD with two partitions: /boot and LVM. In this computer, the lvm partition is the first one (/dev/sda1); I guess that is how ubuntu used to do things.

During the last OS upgrade someone told the updater to put grub on the first partition. As a result, the lvm partition got rather unhappy. Is there a way to retrieve data off that partition?

What does "rather unhappy" mean? The upgrade process remembers what device you installed grub to before and uses the same location when grub needs to be reinstalled. Also, installing grub to /dev/sda1 only modifies sector zero, which LVM does not use, so while it may not boot, it wouldn't cause any harm.