JAIC come to the conclusion that the ship could not sink only from water entering the cardeck. The conclusion is the same made by other ship architects and experts. In the long term however the ship could sink as a result of a total capsize to an up side down position as following a flooded cardeck.
If the cardeck had been flooded with no water at the deck 0 and 1 under the cardeck, the ship had turned up side down and then been floating on the air trapped on those decks under the waterline. This is carefully described in the book "Lies and truths about the M/V ESTONIA" by the Naval Architect Anders Björkman.
The ship did not capsize to 180 degrees, in fact it capsized to 90 degrees with a relatively stable condition around 30 degrees starboard list for a period of time. At this time water could not yet have entered through any windows or doors at deck 4 and 5. Nevertheless, most of the survivors from the lower deck 1 had already left their cabins, and in fact several of them left before the list occurred because of water entering their cabins.
Survivors leaving their cabins at deck 1 noting water on this deck or from the deck 0 below:
Y.W. Cabin 1027
H.W. Cabin 1047
C. Ö. Cabin 1049
A. A. Cabin 1056
A. J. Cabin 1056
C-E. R. Cabin 1094
J. S. Cabin 1120