Problem exists in Chrome for sure (it sends cookies as they are - set with JS for example).

I have two another examples that can make this issue more clear:

>>> from Cookie import SimpleCookie
>>> c = SimpleCookie()
>>> c.load('a=b; c=c"c; d=d')
>>> c.output()
'Set-Cookie: a=b'

Also using escaping and quotes (cookie version 1) works:
>>> c = SimpleCookie()
>>> c.load('a=b; c="c\\"c"; d=d')
>>> c.output()
'Set-Cookie: a=b\r\nSet-Cookie: c="c\\"c"\r\nSet-Cookie: d=d'
>>>