At the point where a transaction is aborted, it's active flag becomes false - either implicitly (because the abort happens outside a callback) or explicitly due to a call to abort() ("...this method sets the transaction's active flag to false...")

In the steps for aborting a transaction, the any requests in the transaction's request list whose done flag is still false are run through sub-steps including:

"Fire an error event at the request. However when running these steps, ignore any request to run the steps for aborting a transaction as those steps are already running."

Which indicates the steps for "Fire an error event" are processed, which includes:

2. Set the active flag of transaction to true.

The clause in the steps for aborting a transaction should either be changed to read:

"Fire an error event at the request. However when running these steps, ignore any request to run the steps for aborting a transaction as those steps are already running, and do not set the active flag of the transaction."

Or the steps for aborting a transaction should drop the "fire an error event" reference and in-line the relevant steps instead (that'd be step 1 and parts of step 3)