I would try two things:
In the "script" field on the record producer itself, can you add a "gliderecord" script block to create the additional incident?
If that doesn't work, then I would suggest a business rule, probably on the produced record table, triggered off the record producer linked, and again, create the additional incident with script.
However, what is the goal for this? If it is to create work for multiple groups against the same incident, then i would suggest harnessing incident task instead of creating two incidents. Creating two incidents could skew metrics because you're doubling the number of incidents. By using incident task, you can assign additional work without an impact to the metrics.
