Bedankt voor je oplettendheid en je correctie, Ab. De tekst is inmiddels aangepast.

Volgens mij had Buwalda de rang van Sergeant-Majoor-vlieger
Bron: Min v Def
https://www.defensie.nl/onderwerpen/onderscheidingen/dapperheidsonderscheidingen/databank-dapperheidsonderscheidingen/1948/11/04/buwalda-j-j

Hartelijk dank voor deze aanvulling, V. Roelen! Mooi hoe we zo een steeds gedetailleerder beeld krijgen van wat er zich precies allemaal heeft afgespeeld.

Buwalda zegt dat hij een auto los kreeg die hem naar Numansdorp bracht. Dat klopt niet helemaal, er lag toen immers nog geen brug. De auto bracht hem naar Willemstad, vandaar is hij overgestoken naar Numansdorp. Dat weet ik vrij zeker, het was nl. mijn grootvader (die had een garage en taxibedrijfje) die hem heeft gereden. De G1 is later door de Duitsers geborgen en volgens mijn vader heeft in ieder geval één van de vrachtwagens met brokstukken bij de garage van mijn grootvader brandstof getankt.

Dank voor deze waardevolle verwijzing en aanvullingen, Ed. Wat een indrukwekkend verslag; in het bijzonder het geval van de Vijfde Man.

from: http://www.polishwargraves.nl/ned/z1475.htm

15.10.1942 Crash of WELLINGTON Z 1475, code BH-X

CREW:
kpr.pil. - Sgt. SZYMEN Czesław
por. nawig. - F/O SOBOLEWSKI Piotr
kpr. r/op. strz. - Sgt. PIĄTEK Stanislaw
st. szer. strz.- Sgt. BIĄLY Lech Józef
st. szer. strz. - Sgt. MIELNIK Michał
R.A.F. Polish
Crash of a Wellington
According to German and Allied sources, four Wellington bombers were shot down by German night-fighters above South-Western Holland on the evening of 15 10.1942.

Three of them got lost without any trace. The 4th Wellington crashed south of the small city of Zevenbergen in the quarter called Hazeldonk.
The burning aircraft approached from western direction and exploded. Around the remnants of the aircraft four bodies were found. They were temporarily buried as "Unknown Airman" on the Cemetery Zuylen at Breda.
After the war these Unknown Airmen were exhumed to the British War Cemetery at Bergen op Zoom, where they are now resting as "AN AIRMAN OF THE 1939 -1945 WAR" in Plot 24, Row B, Grave 8/9 en Plot 27, Row A, Grave 1/2.
On one of the graves the addition "A SERGEANT" is mentioned.
The municipal-police of Zevenbergen drew up a report of this event, in which is written, that on October 15 in 1942 at 23.15 h. a burning aircraft crashed. The report also mentioned what was found.
The Raid Precautions Department of Zevenbergen also made a report, in which the fact was mentioned that, after an air-fight on 15.10.1942 a burning plane crashed from western direction.
About the identity of the plane and its crew nothing was mentioned, but that omission was usual. For according to the Conventions of Geneva, identification of victims should be executed by the German occupants.
One of the official reporters was mr. Van der Mooren, Constable of the Military Police of the Zevenbergen Brigade.
Later he told during an interview, that German soldiers indeed took the personal possessions of the perished airmen, but this fact hasn't been reported in the police-warrant naturally.
The following rumour explains why also later no identification was possible:
Added to this is the fact that soon the rumour spread at Zevenbergen, that the members of the crew were Poles.
The German soldiers, who had the personal belongings with them, became drunk in a bar at Zevenbergen later-on. There they threw these articles into the stove, to revenge the fact, that in Germany the house of one of them had been bombed down!
But constable Van der Mooren told even more:
There were characters on the aircraft we didn't use and that is why he supposed the crew to be Polish.
Indeed, that night Wellington Z1475 of the Polish 300 Squadron Polish Air Force (PAF) Polish Wellington Z 1475 which had taken off from the base Ingham at 18.40 hours and that was probably the explanation that somewhere on the wreckage a Polish text may been seen.
But there are known two other indications which confirm this conclusion. In case you are interested in these details, you are able to mail the webmaster.
With the data known so far it isn't possible to identify persons. So, all we can say is, that the four Unknown Airmen at Bergen op Zoom are Polish Airmen from Wellington Z 1475' crew.
The Fifth Man
So, four bodies have been found, but the Wellington had a crew of five men aboard. The four victims found had been lurched from the aircraft. It is possible that the fifth man has been burned totally in the fires of hell.
An other possibility is that the fifth man happened to see a chance to leave the aircraft earlier and perished in his attempt.
At Bergen op Zoom namely, next to two Unknown Soldiers from Zevenbergen there is also buried an Unknown Airman. The origin of this grave isn't known so far.

De Mk IV werd gebruikt door drie Poolse squadrons, No.300, 301 en 305.
No. 300 (Polish) "Land of Masovia" Bomber Squadron (Polish: 300 Dywizjon Bombowy "Ziemi Mazowieckiej")[1] was a Polish World War II bomber unit. It was fighting alongside the Royal Air Force and operated from airfields in the United Kingdom. 15 Oct Vickers Wellington Z1475 (BH-X) Probably shot down over the sea, while on its mission to bomb Cologne. F/O Sobolewski, Sgt Szymen, Sgt Piatek, Sgt Mielnik, Sgt Bialy all KIA