On some desks, there will be a pad button which will put -20dB cut to the signal before it hits the desks pres. If your soundguy doesn't engage brain or doesn't have this facility available to him/her, there is another solution.
I also have amps with hot DIs, my solution? An inline -20dB attenuator, easy to make, easier to buy off eBay. [url="http://www.ebay.co.uk/itm/XLR-BALANCED-ATTENUATOR-IN-LINE-VOLUME-20dB-/190680441716?pt=UK_MusicalInstruments_Other_Pro_Audio_Equipment&hash=item2c6570a374"]http://www.ebay.co.uk/itm/XLR-BALANCED-ATTENUATOR-IN-LINE-VOLUME-20dB-/190680441716?pt=UK_MusicalInstruments_Other_Pro_Audio_Equipment&hash=item2c6570a374[/url]
Probably worth getting a short XLR to run from your amp to your attenuator and then the soundguy can plug into the otherend of the attenuator. Having the attenuator sticking straight out of your amp is asking for it to be knocked...
Hope this helps.