In Erlang, commas and semicolons are separators not terminators. So you are in fact disallowed to have a semicolon at the end of a sequence of clauses, it's either nothing (for case) or a period (for functions)
It's definitely weird, but it allows for neat stuff e.g. in Emacs' erlang-mode when you type a semicolon it automatically creates a new clause (function or case) for you.