Minecraft wiki entry for Experience, associated text: Before Beta 1.9 Prerelease 2, the score on the death screen always read &e0.
This was caused by an error with coloring the text. In Classic (including the Survival Test versions which featured the original score system), the '&' character was used to color text, so '&e0' would produce '0' in bright yellow. This was later changed to instead use the '§' character for colored text, but because the death screen hadn't been updated with this, the raw formatting code was shown.