Drools OOM when loading session

I ran into an issue loading the session from my JPA.

I am getting this stacktrace:

http://pastebin.com/PMKpdBWM

This is happening for this rule:
http://pastebin.com/HZmLmsEH

And this module:
http://pastebin.com/2Q6k73tC

What I am doing is:

1. Create a new session
2. Insert an ApplicationEvent
3. fireAllRules
4. Reload -> OOM

The ApplicationEvent has a list of 6345 facts in there. I load them from a CSV file, and use drools to insert them into my knowledge base as facts.
When I restart my server and have the session reloaded, it ooms when trying to deserialize the session.

I am still looking for a workaround. I am not sure what is happening and could not find any more info at this point.

I am using:

JPA + Hibernate 4.2.21.Final
org.codehaus.btm:btm:2.1.4 as a standalone JTA platform

Let me know if there's any other info needed.

Thanks,

Artur