A couple of points now then...
When you measured voltage without the diode in circuit you measured the volts that your DMM, 'wanted'. When you measured the volts with the diode in circuit you measured what the diode, 'wanted'. That's how these linear drivers work, they supply the correct voltage that is required to maintain a selected current so as you turn the input voltage up, your DMM will measure higher as it then, 'wants', more, but your diode will still only require 2.47V. (I think that's the correct description... )
How were you measuring mA again? In series with the diode or in parallel? It actually sounds like you just hooked up you meter to the LD outputs as if it were your diode, correct? This is not the right way to do it and will not set the driver. If we go back to what the driver needs to properly regulate the current, (~2.5V), then you were putting in 5.16V and getting 4.69V at the outputs. The driver couldn't hope to regulate with only 0.47V. The driver would not have been in correct regulation and you could have been putting way too much current to the diode. I suggest what the RCKSTR manual was actually trying to tell you was to connect the meter in series with the LD output leads and measure the current as a flow through the diode. Another, and perhaps safer way, (for the diode as it minimises disconnection risks), is to again measure current in series but at the input to the driver. The input current is the same as the output current.
The problem you had is an excellent example of why we set current with a Test Load. It nails the current before ever risking a diode. When replacing the Test Load with a diode it must be remembered to short the driver outputs to discharge the capacitor or you can give your LD a spike it will never forgive you for!
Also bear in mind that some drivers, (namely Dr.Lava's), do not respond well to being powered with no load. And when I say do not respond well, I mean they die! These MUST be set with a Test Load and only ever powered after that with an LD in place.
I suspect you have damaged your diode but now that you have, you can check current in the correct way just to show yourself, (and us), that you have more than 200mA going through it, although your meter doesn't read any higher than 200mA does it. Hmmm. A new meter should now be on your tools list I think.
I hope that's more help and you get up and running soon. Dare I mention goggles? Sounds like you are after quite high powers and you should be using them already...
M