How much influence can HR departments have on sanctions and dismissals?

In the recent case of Ramphal v Department for Transport, the EAT looked at a HR department’s influence over the decision to summarily dismiss an employee for gross misconduct.
Although in the case at hand, the investigating officer found that there was misconduct, he did not himself believe that it warranted a dismissal, but a final written warning.
It wasn’t until further communications between the officer and the HR department took place, that any favourable findings were replaced with critical comments, leading to the recommendation of summary dismissal.
The EAT found that the HR department had advised on issues that went beyond matters of law, procedure, and the level of sanction that would achieve consistency. The dismissal was therefore held to be unfair.
What does this mean for employers?
Where an employer is acting as an investigating and disciplinary officer, the support of the HR department is often invaluable.
However, any advice from HR should be limited to questions of law and procedure, and should not influence an outcome. They therefore must not advise on culpability or appropriate sanctions, unless they relate to consistency.
Employers should therefore be wary as to how much their outcome relies on any advice given by HR personnel.