Server 1 and 2 both run an admin system mod which means admins can have an influence on the game such as re-spawning a dead player or spawning infected which would then be included in the stats.

All log files are kept and can be re-analysed when new stat types are introduced.

If you use certain symbols in your steam name it may not appear correctly on the stats pages due to character encoding differences and will most likely be removed during processing of the data.
The last name you use at the time of processing will be the name that appears in the stats list.

Mayhemgaming #1
Mayhemgaming #2