Hi Ed,
My Dad said that the recon team was from the 5th Rangers, but he may not remember exactly. The bulldozer was pulling a sled with matting to give support to wheeled vehicles exiting the beach. The dozer was intended to penetrate the six foot high wall of shale pebbles that lined the beach in that area.
His LCT-544 was in the fourth wave, and came in about 40 minutes after the show began. They were supposed to land at Fox Green, but when they approached the beach, they were driven off by heavy fire. This area was supposed to have a couple of companies of infantry, as well as a number of DD tanks already landed, but only a single LCT (my Dad thinks it was LCT-25) was there unloading tanks directly on the beach. All of them were knocked out as they landed, and the LCT was destroyed.
His skipper motored down to Easy Red and found a place to land in the area of St. Laurent, to the west of the Colleville draw. At that point, no-one had moved beyond the shale wall. The dozer was wired to the jeeps. The driver raised his plow balde as they dropped the LCT's ramp, and drove off under HMG fire. The LCT had beached on a runnel, as the dozer drove off, it went underwater and pulled the sled and the jeeps through to the beach on the other side.
My Dad never found out if any of the men survived.
My dad took some pictures of the action that you can see on Nav Source under LCT-544, and he made the big time in Ambrose's D-Day book, look under William O'Neill in the index.