I’d be surprised if you could help it at all. It sounds like a sampling error. Does their phone always do that? Back in the bad old days, we used to get a similar problem when a power supply failed inside a piece of audio equipment. Most of the time it would just hum like crazy, and it would be obvious what happened. Sometimes it would chop the show sound in 60 or 120 snippets per second and it would sound exactly like that clip.
Without ripping the clip apart with the tools, I bet there are really tiny times when the speaker’s voice isn’t there at all.