SDURLCache with AFNetworking and offline mode not working

I'm using AFNetworking and SDURLCache for all my networking operations.

I have SDURLCache set like this:

SDURLCache *urlCache = [[SDURLCache alloc]
        initWithMemoryCapacity:1024*1024*2   // 2MB mem cache
        diskCapacity:1024*1024*15 // 15MB disk cache
        diskPath:[SDURLCache defaultCachePath]];
    [urlCache setMinCacheInterval:1];
    [NSURLCache setSharedURLCache:urlCache];

All my request are using cachePolicy NSURLRequestUseProtocolCachePolicy, which according to apple docs works like this:

If an NSCachedURLResponse does not exist for the request, then the data is fetched from the originating source. If there is a cached response for the request, the URL loading system checks the response to determine if it specifies that the contents must be revalidated. If the contents must be revalidated a connection is made to the originating source to see if it has changed. If it has not changed, then the response is returned from the local cache. If it has changed, the data is fetched from the originating source.

If the cached response doesn’t specify that the contents must be revalidated, the maximum age or expiration specified in the response is examined. If the cached response is recent enough, then the response is returned from the local cache. If the response is determined to be stale, the originating source is checked for newer data. If newer data is available, the data is fetched from the originating source, otherwise it is returned from the cache.

So everything works perfectly even in airplane mode as long as the cache is not stale. When the cache expires (max-age and others), the failure block gets called.

I've been digging a little inside the SDURLCache and this method returns a response with valid data (I've parsed the data to a string and it contains