I think that some of the "Daily Mail" and other newspaper accounts were stories meant to boost morale and sell papers so some of these accounts must be taken with a grain or more of salt. Many were cobbled together from a number of incidents to craft a story.
But there were quite a few incidents where misidentification occurred with individual pilots with tragic results.
Erich Loewenhardt is reputed to have attacked a Rumpler C.IV and shot it up pretty good. (There was an account of an old German pilot in OTF a few years back, Otto ???, can't remember his last name right now.) The aircraft was marked in the standard national markings and camouflage pattern of the Rumpler series but apparently Loewenhardt messed up on that. According to the pilot being interviewed the bullet tore a big hole in the radiator, possibly an explosive bullet.
Also,
Charles Nungesser was jumped by an overanxious British pilot.
Lautenschlager was killed in his new Fokker Dr.I by fellow German pilots who mistook his plane for a Sopwith Triplane.
Also, a pilot from No. 46 Squadron apparently shot down a British Nieuport from a neighboring squadron in Summer 1917.
This was a common problem that reflected the rapid rate at which pilots were being pushed through the training system.
The Winter Issue of Over The Front will have an interesting article on Groupe de Combat 14 by Bill Bailey and Alan Roesler that includes an instance of this nature and how it impacted the military of the two respective allied countries to try and solve the problem.
Aaron