asterisk users - Oct 2005 - Asterisk Busy Detect

Hi,
Is my CLEC feeding me a line, or is this really how it has to be?

When I dial a number on their system, if it's busy I get a busy back right
away.

If I dial a number on say Verizon's system, the CLEC sends me a "call
preceding event", and then I get a BUSY back from Verizon.

Should the CLEC be able to only send me ahead if Verizon says "go
head" and give me a BUSY if Verizon gives a BUSY?  Rather then just
blindly passing me off to Verizon?