BoogerMan
Which "one" person were you referring to - Professor Buckhaults, or Kevin McKernan?
The study of DNA is a huge topic and to suggest that any untrained person fully understands the whole story after watching a video for a few minutes is ridiculous.
All of us ingest plant and animal dna, and sometimes human DNA when we eat. The body has methods to ensure that this DNA is broken down and can't cause any problems.
This is the short answer. I'm not an expert. From what I understand of this video, the professor was bringing attention to the need for scrutiny concerning regulations.