7.38Mule cannot magically roll back Salesforce

This is crucial.

Suppose:

Salesforce Account create SUCCESS
     ↓
Billing API create SUCCESS
     ↓
ERP create FAILS

Then:

On Error Propagate

does not automatically travel back in time and delete:

Salesforce Account
Billing Customer

Mule transaction rollback semantics apply only to resources participating in the relevant transaction mechanism. External SaaS calls are not automatically one giant distributed transaction. Mule's transaction docs make transaction ownership/boundaries explicit.

So you may need compensation.