The Crown could bring (attempted) murder charges
new-south-wales
s18 of the Crimes Act 1900 defines murder as:
Murder shall be taken to have been committed where the act of the accused, or thing by him or her omitted to be done, causing the death charged, was done or omitted with reckless indifference to human life, or …
The Judicial Commission has this to say about recklessness:
Reckless indifference to human life is the doing of an act with the foresight of the probability of death arising from that act: The Queen v Crabbe (1985) 156 CLR 464; Royall v The Queen (1991) 172 CLR 378; Campbell v R [2014] NSWCCA 175 at [304].
The defence will almost certainly raise that the actions of the defendant did not cause the death and that's a significant hurdle for the prosecution to overcome.
Causation is a question of fact. There can be more than one cause of the injury suffered by the victim. It is wrong to direct the jury that they should search for the principal cause of death: R v Andrew [2000] NSWCCA 310 at [60].
In a murder trial, proof of the element that the act of the accused caused death requires the jury to be satisfied beyond reasonable doubt that the act of the accused was a “substantial or significant cause of death” or a “sufficiently substantial” cause: Swan v The Queen (2020) 269 CLR 663 at [24].
Where appropriate the jury should be directed to consider whether there is any act of the victim that broke the chain of causation between the act of the accused and the injury inflicted upon the victim: McAuliffe v The Queen (1995) 183 CLR 108. In Burns v The Queen it was said at [86]: “Absent intimidation, mistake or other vitiating factor, what an adult of sound mind does is not in law treated as having been caused by another.”
If the victim was one of the criminals or one of the police, this defence would probably succeed. If there was a shootout, then the victim made a conscious choice to engage in that shootout. And further, that risk is inherent no matter where the arrest takes place.
However, if the victim is one of the diner's staff or customers, then there is a real chance that the jury would find that that conscious choice by the accused to wait until those people were there before prompting police action is a "cause" of the death (bearing in mind there can be more than one cause) and that the acts of the innocent victims (barring heroics) would not break the chain of causation.