strange router object behavior

Hello.

Was debugging one my patch and found this weird thing.

Encountered a strange router object behavior. When i have a feedback loop in connections between any router's outlet and its first inlet and when i send some data to a router's inlet (as in this example patch, the lower number box), i get all data + dump output being sent through the first router's output. Sending data directly (the upper box in the example patch) woks fine. The explanation is quite messy, but you can try the attached patch to clearly see what i mean.

Maybe I didn't understand the logic of why this works and it would be nice if someone can explain me that (to know the basics better). Also I haven't found any information about such behavior in the documentation, it would be also nice to have this included in the tutorial.

Thanks.

MaxMSP 5.06 / OS X 10.5.5