deep water = less ejecta?

[john bois <jbois@verizon.net>]

OK...so the Chicxulub crater is shallow because the bolide hit in deep 
water...thus sending massive water into the atmosphere and, at the same 
time, cushioning the blow to underlying solid materials.  Do we now have to 
downgrade the amount of re-entering ejecta and associated fire storms, heat 
pulse, and toasting as a killing mechanism?