Thanks for the reply. That does work.
I also managed to work around it (without replacing it) by using the following to transfer variables I wanted:
import groovy.json.JsonSlurper
def response = context.expand( '${name#Response}' )
log.info "response: "+response
def slurper = new JsonSlurper()
def json = slurper.parseText response
def String stringExecutionId = json.executions.id[0]
log.info "ExecutionId: "+stringExecutionId
testRunner.testCase.testSteps["Properties"].setPropertyValue( "executionId", stringExecutionId );
