Question regarding ACL in N10-004 Book

[theevenger]

I am confused by a diagram in your book "CompTIA Network+ Study Guide 2009 Edition" (ISBN 978-0-470-42747-7)

My question is regarding the ACL diagram on page 504 in Chapter 15 (Physical and Hardware Security). In the diagram, the private network is network A, and the public network is network B. According to the ACL, A can access B. In the explanation text, it talks about how in an IP Spoofing incident, someone spoofing an address inside the firewall could still access network B. I think this might have been a typo. Should this have read, someone in network B (the public network) could access network A (the private network) by spoofing an address inside the private network? Otherwise it doesn't make sense, since the private network was always able to access the public network.