(Disclaimer: While this question pertains to interpersonal issues in a working environment, I feel it is better suited to this SE than Workplace because of it being in the context of a lack of formal responsibility/hierarchy in an academic environment)
The deadline for the camera-ready version of a publication and conference registration is in seven days; In order to finalize the publication, I need to specify information regarding licensing of the primary data (it is literally an HTML field which I have to fill out in order to submit the paper; It is not "just" some legal requirement).
I do not have the experience to decide what licensing is applicable to the type of data I need to license, the hosting setup for the data which will ultimately be in place, and the country/countries involved (I don't even know what countries would have jurisdiction). However, this would in theory not be a problem, because a tenured member of staff, who also said they would settle the issues regarding hosting, said they would "look into it". This person is otherwise not related to the publication or project.
The problem now is that I have been regularly asking the person who offered to deal with licensing issues about the status of the issue for two months now, with the frequency and seriousness of the contact increasing (first it was an occasional e-mail, then more e-mails, then physically finding said person and asking them in person). However, now I have almost no time left, and I still have no resolution to the issues described above.
I do not doubt the person's "trustworthiness" since they are a senior member of faculty in a small department and I know neither this department nor the person very well. Nevertheless, I cannot trust that this person will magically do what I asked of them one hour before the deadline because the stakes are too high. How can I resolve my dependency on this person before the hard deadline, i.e. how can I get them to do what they said they would do when I cannot do it myself and don't have time to find someone else who can? The person is neither my supervisor nor formally part of any project I am working on, so I have absolutely no way of formally resolving this.