rasa data validate shows wrong conflicting action name

[JEM-Mosig]

Rasa version:
Rasa Version : 2.0.0a5 (commit 30d2af7)
Rasa SDK Version : 2.0.0a5
Rasa X Version : 0.32.0

Rasa SDK version (if used & relevant):

Rasa X version (if used & relevant):

Python version:
Python Version : 3.7.0 (default, Oct 9 2018, 10:31:47)

Operating system (windows, osx, ...):
Operating System : Linux-4.15.0-117-generic-x86_64-with-debian-buster-sid

Issue:
rasa data validate shows wrong conflicting action name. Specifically, if a conflict is present (regardless whether in a story or in a rule), it prints Story structure conflict after action 'action', where the last action should be the name of the action instead of the word "action".

Error:
With stories

- story: happy path
  steps:
  - intent: greet
  - action: utter_greet
  - intent: mood_great
  - action: utter_happy

- story: sad path 1
  steps:
  - intent: greet
  - action: utter_greet
  - intent: mood_unhappy
  - action: utter_cheer_up
  - action: utter_did_that_help
  - intent: affirm
  - action: utter_happy

- story: sad path 2
  steps:
  - intent: greet
  - action: utter_goodbye
  - intent: mood_unhappy
  - action: utter_cheer_up
  - action: utter_did_that_help
  - intent: deny
  - action: utter_goodbye

the wrong output is

rasa.validator  - Story structure conflict after action 'action':
  utter_greet predicted in 'sad path 1' and 'happy path'
  utter_goodbye predicted in 'sad path 2'

Command or request that led to error:

rasa init
# now add a conflicting story, e.g. by replacing a utter_goodbye by a utter_greet
rasa data validate