If your process is not running, or dies for some reason, the process writing to this log file will eventually block. This will probably cause the entire process to freeze, as writing to a log file is something that would be expected to return immediately.

Also, if the process writing to the file happens to rotate log files, your fifo will stop recieving data. File::Tail will open the new file and continue happily reading the data at the end of the file.