This is what the current regs state - further guidance is given in AP3393 Vol 4 for religious purposes.
0152. Hair – All Personnel. Canerows, cornrows, twists and braids are permitted. Hair worn in this manner is to be no longer than the bottom edge of the collar of the Service jacket if worn down and must be tied back if longer. All personnel (who chose to) may wear a turban of approved Service pattern and colour, instead of uniform headdress. The appropriate cap badge is to be fitted centrally on the turban. When necessary to wear specialist head gear such as combat helmet or flying helmet, the turban is to be removed and the hair can be covered using a hair net. SP may wear a head wrap when required for occupational reasons (e.g. stewards, technicians, engineers). The head wrap is to be dark in colour with no branding or patterns. These are not to be worn on ceremonial events. Thin hair bobbles, bands or elastics (no wider than 10mm) may be worn with working dress but must be of a similar colour to the hair or black. Hair clips, grips etc may be worn but must be plain and of a similar colour to the wearer's hair or black. Hair beads or hair adornments / jewellery are not to be worn when in uniform. Fabric covered hair bobbles (scrunchies) may be worn with working dress but must be inconspicuous and either of a similar colour to the hair or black. These are not to be worn on parade. Aircrew are not to wear hair clips and grips when flying for health and safety purposes.Hairdressing and Cosmetics - Men.
0153. Hair – Men. The hair of the head is to be well cut and trimmed, permitting service headdress to be worn (“topknots” which compromise the wearing of headdress for example are not permitted). Men may not grow their hair long, unless for religious / medical reasons or to wear their hair iaw para 0152 above. Where it is permitted for hair to be grown longer, hair longer than the bottom edge of the collar must be tied back neatly in either a bun, a single plait or a ponytail. The plait or ponytail should aim to be no wider than the wearer’s head (width of the hair after the hair tie for the ponytail or width of the plait) and where this is unavoidable not beyond mid shoulder. It should be no longer in length than where the top of the belt would be if worn in No 2 Uniform. Where hair is grown as a tenet of adherence to faith, it is permissible for the hair to not comply with the characteristics set out above. All hairstyles iaw this policy must enable service headdress to be worn correctly. Sideburns are to be short, well-trimmed and are not to extend below a line running through the mid-point of the ear. Regardless of hair length, no separate sections of hair may be shaved (this does not mean individuals may not shave their entire head, or have different lengths of hair (i.e. 2 on sides and 4 on top), merely that there must not be an extreme difference in length between the side of the hair and top of the head). This list is not exhaustive, but no patterns; shapes; “undercuts” or fully shaved sides, long on top styles are permitted. Individuals whose hair does not comply with this policy (with the exception of those who have done so for any religious or medical reasons) are to be ordered to modify their hair such that it does. If the hair is dyed or highlighted, the colour chosen is to be natural and in a uniform shade appropriate to the individual. Any individual who does not comply or who is repeatedly found to breach the policy is to be considered for administrative action (either Minor or Major as appropriate to the circumstances). APC or RLO advice is to be sought where there is any doubt. Individual Chains of Command do not need to approve hair styles (such as cornrows and canerows), but are responsible for ensuring that this policy is adhered to.
So in the case of the NCO above, then anyone who works with them are probably not upholding the intent of the AP above. It is quite clear that they break the policy on beard length, hair style and long hair policy.
Finally, my mistake, there are lines in KR209 and KR210 about beards too.