From the article linked by GUEST,999:

36 Matters to be ascertained at inquest

(1) The proceedings and evidence at an inquest shall be directed solely to ascertaining the following matters, namely--
(a) who the deceased was;
(b) how, when and where the deceased came by his death;
(c) the particulars for the time being required by the Registration Acts to be registered concerning the death.
(2) Neither the coroner nor the jury shall express any opinion on any other matters.

Although the "how" in (b) might be subject to some interpretation, the remaining description of the duties of the coroner suggest that the meaning is limited to the physical "how," and according to (2) it would be appropriate for the coroner to instruct the jury that it was not within their authority to determine "wrongful" or "righteous."

Additonally:

42 Verdict

No verdict shall be framed in such a way as to appear to determine any question of--
(a) criminal liability on the part of a named person, or
(b) civil liability.

From the viewpoint of one casual reader uninformed as to precedents and practices, the rules written in the cited article would appear to support what reportedly was done. (?????)

But IANAL, in the UK or elsewhere.

John