Bug? Tasks duplicated when created via URL scheme

I have an URL scheme action that I invoke with Launch Center Pro to add tasks to OmniFocus.

It runs through Fantastical 2 (so that it parses natural language due dates/times), and adds it to a Reminders list, which is then imported into OmniFocus the next time it’s opened.

In Launch Center Pro I type in something like:

Pickup milk tomorrow at 9am

It then opens Fantastical 2, adds the task to Reminders, then opens OmniFocus’ Inbox so I can verify the task was successfully imported from Reminders.

When the action is run if often adds the task twice in OmniFocus, but not every time. If I run the action without opening OmniFocus straight afterwards then the task is never duplicated.

Here’s the Launch Center Pro action


Is this a bug with OmniFocus? Does the action produce duplicated tasks for anyone else?