An issue reveals itself if the process writing to the tail'ed logfile writes more than one line in a write().
To reproduce:
$ echo 1 >> /tmp/myfile
$ echo 2 >> /tmp/myfile
$ echo -e "3\n4" >> /tmp/myfile
$ echo 5 >> /tmp/myfile
I fixed this by patching line 37
37 #print fh.readline().rstrip()
38 for line in fh.readlines():
39 print line.rstrip()