Guys, I beg to differ. I see mainly serious replies to the OP's questions.
This question does tend to come up regularly.
Here's a thread a couple of months back:
http://vboards.stratics.com/showthread.php?p=1576234
Like Dermott mentioned, this is verifiable using EC.
Just wear 45 dci, then have your guidie hit you with a weak HLD weapon until you hear the HLD sound effect. Confirm that your dci has gone down by 25 and continue to have your guildie swing at you for 100 more times. Notice that you are getting hit more often.
Now repeat the test by over capping your dci to 70. EC will still show that your dci is 45. Have your guildie hit you with the HLD weapon until you hear the HLD go off. Verify that the EC still shows you that your dci is 45. That is because the extra 25 points of dci would provide a buffer to offset the 25 point dci penalty from HLD. Continue to have your guildie swing at you for 100 more times. Notice that this time around, you are not getting hit more often even when affected by HLD.
Now, because like spoonyd, there are other folks that do not trust the stats displayed in the EC, these people have also done extensive tests to verify that what the EC shows in this case is accurate.