I think it has to do with the survivors' contradictions as well and how the examiner's opinion might lean towards one account and dismiss another or vice versa. e.g. In the first video we hear an explosion and see a cloud of sparks coming out of the funnel but we don't know who's accounts were used. e.g. Harold Bride said - "Smoke and sparks were rushing out of her funnel. There must have been an explosion, but we heard none. We only saw the big stream of sparks."
Examiner A - He might trust the source entirely but direct his attention to the quote "There must have been an explosion, but we heard none." and he would create his own hypothesis as to why Harold Bride did not hear the explosion e.g. in shock or submerged underwater, and hypothesise what caused the explosion to occur. e.g. electrical cables snapping, boilers exploding or imploding, or the break up occurring.
Examiner B - He might trust the source entirely as well and direct his attention to the same quote but with emphasis on the latter part "There must have been an explosion, but we heard none." and he would add his own hypothesis as to why there was no explosion or explosive noise when Harold Bride saw the sparks e.g. compression of air and steam causing hot coals and dust to shoot out of the funnel.
Examiner C - He might dismiss this account entirely because it was published in the New York Times and he might not accept this as a credible source regardless of whatever it said.
Examiner D - He might trust the source 50 percent but would take for granted that the reporter had exaggerated a word here or there to make his article more sensational for the readers, and therefore he would not take the account in the literal sense, but would instead read between the lines and get a rough idea as to what the witness might have really said.
Examiner E - He might trust the account partially as well because the witness had admitted at the official Inquiry that he gave the interview to the New York Times in front of witnesses and that he was paid handsomely for it. Although the witness (Harold Bride) did not confirm or deny that every word in the report was accurate, and therefore it would be up to the examiner to make his own judgement as to how authentic the report actually was.
Examiner F - He might believe Bride's official testimony at the Inquiries was more truthful than his report to the New York Times and might dismiss the idea that sparks came out of the funnel.
Examiner G - He might believe the opposite and believe that Bride's report to the New York Times was more honest, open and truthful than his official testimony at the Inquiries and believe he was under pressure by his superiors at the Inquiries.
Examiner H - He might believe the accounts that were made as close to the sinking were more truthful than those accounts made in the weeks, months, or years after the sinking, and base his opinion on how much the witness could remember.
Examiner I - He might add up all the survivor accounts that mentioned the sparks and would compare it with those who did not see any sparks and he would base his belief just on what the majority saw.
Examiner J - He might do the same but instead he would evaluate when they gave their statements, if they were first hand or second hand, if the sources could be trusted, and if the witnesses were in a good position to see the sparks, both physically and mentally owing to the dramatic break up and sinking of the vessel and then work out that the majority may turn out to be the minority in regards to who's accounts were more believable.
Examiner K - He might use scientific analysis based on the best speculations that they could offer and believe the accounts that followed their analysis and dismiss the rest.
Examiner L - He might use his own experience to determine what really happened as they were emotionally and physically in a similar position and would give preference to the accounts from survivors who endured a similar experience that he could relate to.
There are so many possibilities and ways to evaluate one single piece of testimony that it is very hard to accurately determine what really happened. An open porthole, or a cracked pipe, or a door wedged open or a door jammed closed might have played a key role in how the ship's flooding progressed and how this may or may not have ultimately led to her listing to port or starboard, or tilting, or breaking in two. You can see how difficult it can be to confirm exactly what really happened. A simulation will always be limited to our own beliefs as to how the ship sank rather than how she really sank. Although with hard work and determination they could come up with something pretty close, but even then, there will always be that element of bias and speculation integrated into the simulation to fill in the blanks.
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