After a little looking it appears that the tool you are using to investigate this PDF document is standalone python(?) tool written by a "security researcher". I put that title in quotes simply because I know nothing about him, other than the fact that he claims to be a security researcher and likes putting his name on his website.
If none of those options appeal to you I would try to look at this as a risk/benefit analysis:
- Do you have any reason to distrust this PDF file?
- Did it come from a reputable source?
pdfid -d is supposed to do, but considering that I know nothing about the tool that would be something best directed to the author.
If you are on linux something as simple as:
pdf2ps input.pdf - | ps2pdf - output.pdf