Originally Posted by GobonaStick
This map posted by the witness seems to point to 05:00 (time zone unclear), assuming the section highlighted is where the sighting took place.
The timezone was most likely UTC+8 (the software her husband used to create the plot uses local time), in which case that section of the plot missed MH370 by a couple of hours or so.
However since the yacht only does 3 knots so it would definitely been possible to see the airplane assuming that the ATSB estimated track is correct.
At 02:50 the yacht was on a northern tack so MH370 would have appeared over the bow, then swung around the port side and disappeared off to the stern. Her eyewitness account saw something over the stern and traveling from port to starboard, so that would be West to East, completely wrong for MH370
As for what she saw it was dawn so it may have been a plane catching the red glow of sunrise. The 'other aircraft' she saw could have be low-earth orbit satellites, which would have been clearly visible at that time of day.