Whilst many have found Mr Cummings' actions intensely frustrating and indeed the moral side to this, (outside of the law) is that leaving one's house during lockdown without good cause, contributes to greater spread of the disease, a charge of manslaughter would not likely be levied against him.
Before evening looking at manslaughter - the The Health Protection (Coronavirus, Restrictions) (No. 2) (England) Regulations 2020 mentions here:
"A person who without reasonable excuse contravenes a requirement in
regulation 4, 5, 6(10), (11) or 7 commits an offence."
'Reasonable excuse' based on concrete facts is something that would have to be explored by police, CPS etc - and then even argued by the defendant's lawyer if needed - before being convicted of this offence - not just by the media.
But, accepting the academic discussion of pursuing a manslaughter charge if the defendant were found guilty of breaking this law:
Murder & Manslaughter
Manslaughter can be committed in one of three ways:
- Killing with the intent for murder but where a partial defence
applies, namely loss of control, diminished responsibility or killing
pursuant to a suicide pact.
- Conduct that was grossly negligent given
the risk of death, and did kill ("gross negligence manslaughter"); and
- Conduct taking the form of an unlawful act involving a danger of some
harm that resulted in death ("unlawful and dangerous act
manslaughter"). The term "involuntary manslaughter" is commonly used
to describe manslaughter falling within (2) and (3) while (1) is
referred to as "voluntary manslaughter".
The assertion of the charge would fail at the first hurdle, given the CPS and legal requirements. But, even if we plead ignorance to this for the purposes of discussion:
The first problem pertaining to a specific charge of manslaughter being levied against Mr Cummings is that one has to have a victim (or plural) who has died as a consequence of Mr Cumming's actions (but for his actions, this death would not have occurred). Expert witnesses would almost certainly testify that any alleged victim died from the effects of coronavirus and that is impossible to definitively say where this was contracted from and how it coincided with Mr Cummings actions. Given specifically that this infringement was before 'track and trace' etc - and in quite a preliminary stage of lockdown and a great many people may have carried coronavirus. If you were even talking about limiting the scope of this discussion to simply his journey in itself, there is not (to my knowledge) definitive evidence that Mr Cummings actually had coronarvirus himself... etc.
A manslaughter charge would then fail on the grounds that one could not prove an unbroken chain of causation between Mr Cummings' breach of the legislation: The Health Protection (Coronavirus, Restrictions) (No. 2) (England) Regulations 2020 and the victim's death. There are too many uncertainties and possibilities that render Mr Cumming's liability remote to say the least. There is a rather good essay focusing on chain of causation and manslaughter here.
It is my impression that some would like a serious criminal charge levied against Mr Cummings and thus the reason for questions like this. Moving aside from manslaughter into procedural matters - pursuing an individual that broke lockdown once or twice (as far as we know), beyond statutory fines, or to create a serious offence of it (eg "being outside your own home during lockdown without good cause = endangering life") is not a step that parliament, the CPS or judiciary would likely pursue as it would open the floodgates of 'necessitated' prosecutions and the practical effects of this would be very difficult if not impossible to manage. Could everyone who left their house be (remotely) liable for the death or injury of another? This is not the same as coughing in a keyworkers face, for example (see CPS here). There is also a fantastic Oxford article on criminal issues pertaining to spreading coronavirus here.
You have mentioned that you feel Mr Cummings has encouraged people to behave recklessly. Encouraging a crime is an incredibly complicated area of law - see here and here - and 'encouraging recklessness' is even more complicated still!
As a further point of interest to this question; there is currently an attempt to privately prosecute Mr Cummings for breach of this legislation - however, the point has been made that currently the only people who can prosecute Mr Cummings are the CPS or government, as private prosecution for infringing the Coronavirus legislation, is not possible under the Public Health (Control of Disease) Act 1984 - see here)