How short can the gutta percha be?

I was doing an RCT today and I couldn’t get to the bottom of the distal canal. The tooth had a lot of shadowing on it and I explained to the patient it was too short. I tried negotiating getting down more but couldn’t. So I referred.

Patient did want me to continue and seal. But has history of being a high demand patient. Even though he said he didn’t care at that moment. Would have this been okay to take a chance on?