I have reported this beforehand, which might have been the wrong thing to do before posting to the Q&A Forum, but it seems my point was missed by the person responding to the report, so I'll try to see if this is a better place for a more fluid conversation.
I'm not a native speaker of either English(though my proficiency level is definitely not low) or French(not so good with this one yet), but it seems to me that both *I'm going to go* and *I will go* can be used for immediate future (whatever ''planning'' arrangements might be), and it's rather ambiguous in the french sentence to deduce that *am going to go* should be used over *will go*, thus to me it would seem that both variants should be accepted as viable answers.
I would be glad if somebody could clear up why one is acceptable, and the other is not.
Thank you.