I think mr Myers is suggesting by this quote
“Mr Myers is now questioning Dr Bohin, he puts it to her that there is 'not much' to support her conclusions. She says that the infant suffered a cardiac arrest, 'something caused that, the baby almost died...for me air embolus fitted with that'”
about the lack of symptoms just before the collapse. Ie the baby had a heart attack without warning. he might be right in that regard. Would the baby not have been in any pain immediately prior to the collapse?