BUG #1507: CREATE RULE commands atomicity

The following bug has been logged online:

Bug reference: 1507
Logged by: Alexis Wilke
Email address: alexis(at)m2osw(dot)com
PostgreSQL version: 8.0.1
Operating system: Linux (not relevant)
Description: CREATE RULE commands atomicity
Details:

I read the page about CREATE RULE and Chapter 33 which explains the rules
and I couldn't find anything about whether rules are atomically executed
(i.e. is there an implied BEGIN/COMMIT?)

My point here is if I write one INSERT command somewhere which is
transformed by a rule, I'm very likely
not going to write BEGIN + COMMIT since to me it will look like one
instruction and I expect it to be
atomic by itself.

Is that a correct assumption?!

Thank you.