Forget about a 19 min five km test run legitimizing his marathon times. A 2:52 marathoner should be able to run at least a 17:40 five km test run. I'd wager $100 (Canadian, haha) that he couldn't break 20:00. Ed just informed me that he will kick in another $100 (Canadian, again).
It’s always possible that you are correct ... or not. No real evidence has been posted other than one DQ out of many races. If you look at the results of the race I just posted, you will see numerous runners within 1 minute of his finishing time with 5k PRs of under 18 minutes. Apparently, you must be claiming that he cheated in this relay race as well. Maybe he did.
$100 doesn’t mean anything. If you’re so sure, maybe you can commit to $5,000 towards his running club if he breaks 19 minutes. I’d prefer to wait for real evidence one way or the other before proclaiming guilt.