In reply to Reach>Talent: Walls in England/Wales must comply with various legislation in common with other sporting facilities including:
The Occupiers Liability Act 1957
Health and Safety at Work Legislation
Employment Legislation
Various Discrimination Legislation
Work at Height Regulations 2005 (2007) Amendment
PPE inspection regulations (PUWER, LOLER and WAH Regs are all relevant)
Walls constructed since its introduction must meet BS EN 12572
Scottish Walls fall under slightly different laws but they come to the same thing.
The sort of procedures you are referring to would come under the second of these areas. Walls are seen as 'sporting facilities' and as such are subject to inspection and enforcement by the Local Environmental Health Officer. Owners and Managers should ensure:
1. The facility is safe
2. The facility is properly equipped
3. That safe practices are used
4. That adequate training and supervision is available
The route to fulfilling these responsibilities will vary from wall to wall and owners and managers should take 'all reasonable precautions'. Thus a small private school wall might have very different procedures, staffing etc. from a large, busy commercial centre.
Guidance on what is appropriate is available from the principal trade body The Association of British Climbing Centres
http://www.abcclimbingwalls.co.uk and The BMC through their Climbing Walls Officer Rob Adie and their excellent Climbing Wall Manual (which much of the above information is drawn from)
https://www.thebmc.co.uk/the-bmc-climbing-wall-manual
In terms of staffing IRATA type competencies are relevant to maintenance issues and some rescue situations on the walls but most staff will be competent through a combination of Mountain Training NGBs and/or Site Specific Training and Assessment which should (IMHO) cover foreseeable incidents such as the one you mention. This training is usually provided by a knowledgeable MIA/MIC/Guide with extensive climbing wall experience.