With a chair behind him.
Who is this "everyone" who "agrees there was a kitchen fight"? Whilst the kitchen may have had that appearance -it was certainly disrupted- there is only speculation as to how it came to be in that state.
Of course there was a kitchen fight.
Some supporters claim Neville got to the kitchen and then meekly collapsed over the coal scuttle. And then the raid team started smashing things and knocking things over.
However it was impossible to inflict Neville's severe facial and body injures in his position. And pointness doing it if he was not fighting back.
It's always been preposturous that the raid team caused all that mess.
Neville either landed over the coal scuttle during the fight and after getting the injuries. Or was moved there. Which only Bamber could/would do. Either way, it wasn't Sheila who fought him as she did not have a mark on her.