Here's an idea wrote:
My fastest 10k pr was a minute faster than my second fastest time. I had 4-5 10k's around that second fastest time. What was the difference? I had a friend who paced me for the fast time. Why don't you offer to pace this guy? You could set out at 6:20 which would build a little buffer. I would be willing to bet that if this guy has been training hard and is close to 20, a little help from you could get him under.
It can be interesting pacing folks who feel like they give their all. Some of them you can show how to actually run hard over a long distance and others will hold longwinded conversations as to why they can't go any faster.