Just tried it. It's a lie. My +24% smg damage relic boosts my SMG damage to 22k while Shock just leaves it at 15k. However, I do hit shielded enemies for 50k with my shock weapons (and the relic equipped).
I just tried to retest it, and you're right. It was a lie. I don't even have a shock relic. I had done some shock combo tests with my mechromancer not too long ago and thought that included a relic --- How's my posting? Call http://boards.gamefaqs.com/gfaqs/gentopic.php?board=588037 for any comments.