The ignorance of some people knows no boundaries.
If they had taken the trouble to do the minutest bit of research, they'd save themselves the shame of revealing their ignorance.
"The position and depiction of the flag is correct; the depiction of flags by airlines on the exterior of the aircraft has it origins in shipping, where the ensign of the country is flown off the stern of the ship.
"In shipping, as in aviation, precedence cannot be established as it would on land by flying a flag from the tallest point, so the stern (or in the case of an aircraft, to the rear of the insignia) conveys precedence (ie shows the country of origin).
"According to flag etiquette, which again traces its origins back to shipping – and was reaffirmed in the earliest days of commercial aviation – a national flag should never be seen to be travelling backwards.
"If the flag were replicated on the starboard side of the aircraft as it is on the port side, when the aircraft is travelling forwards, the flag would, then, be flying backwards.
"From the port side of the aircraft, the flag is viewed as you would expect to see it flying on a flagpost, and when the aircraft is flying, it will fly as it would on a flagpost in the breeze – with the five stars and moon leading, and the red and white sections following.