Randall2n wrote:
SNIP
The first did not raise a question about it, but looked like he was
going to use the lower pipe. The second said he was going to check on
a variance to use the lower pipe, and mentioned something about an
island sink vent.

Go he
http://www.codecheck.com/pg13_14plumbing.html
Fig P-5.

The "island vent" scheme was designed for use in kitchens
where the sink is out on an "island" and can't be vented
vertically. It's a clever scheme which has lots of applications.
I'll be taking bets on whether it will be allowed. g

Good for you for taking the time to get the inspector's input on the
project!

Jim