Out-of-zone data mistaken for glue?

[Phil Mayers]

Following on from yesterdays query; if I have this zone:

test.com.		86400	IN	SOA	...
test.com.		86400	IN	NS	...
foo.test.com.		86400	IN	NS	ns.foo.test.com.
ns.foo.test.com.	86400	IN	A	192.168.254.254
www.foo.test.com.	86400	IN	A	192.168.1.1

...this zone loads fine, and www.foo.test.com does *not* resolve, which 
is as expected I guess. However, neither bind nor named-checkzone report 
the non-glue A record as an error. Is this expected?

(This is just curiosity - obviously it's a bad idea to populate zones 
like this!)