They recognized different naming structures:
Both cameras store the picture profiles as .CPF files, but they follow slightly different naming structures. With the C300, each .CPF file utilizes a prefix with the number 3, so an example of concurrent files would list as CPICT301.CPF, CPICT302.CPF, CPICT303.CPF, and so on. The C500 is similar except the number 4 is used instead, so an example of C500 picture profile files would be CPICT401.CPF, CPICT402.CPF, CPICT403.CPF, and so on.
You can download their profile here.
via CineTechnica