Dear Jochen,
Both loss lists I have, compiled independently by Michel Balss and George Morrison, do show Karl Kaulard KIA 23 December 1944 and his plane a write off, source being BA-MA Signatur RL 2 III/1170, p.5, the same source used in your JG 77 opus (Vol. IV, p. 2218)
There are though three photos of a "Gelbe 7" from 3./JG 77 belly landed near Hotton, Belgium, which are supposedly his machine.
One is published in Erik Mombeek LuGa 4, JG 77, p. 92; the two others, proven to show the same plane, were posted on
www.usmilitariaforum.com, 21 November 2011.
None does show the W.Nr.; the camouflage pattern points rather towards an Erla built G-14, hence no absolute certitude about "Gelbe 7" being Kaulard's machine, though the plane photographed by GI's was indeed part of 3./JG 77. Another difficulty comes from the clean belly landing "Gelbe 7"'s pilot managed: he certainly walked away from it.
Cheers
Marc