We can all laugh about the breaches of Regs that did no harm but they were made for a reason. Failure to test for breaks before charging a hole is in breach of Reg 52(2). The consequences can be serious.
The William Pit disaster of 1947 was caused by the firing of a shot in the roof of a waste (known as a Cuckoo shot). It had not been checked for breaks - there were Regs requiring this before the 1961 ones - and it was charged with a sheathed permitted explosive. It was concluded that (partly due to adiabatic compression) firedamp in a bed-separation cavity had been ignited via a break in the hole before passing to a large gas accumulation in the waste.
As a result of this disaster recommendations were made that the firing of Cuckoo shots be restricted. The 1961 Regs (reg 49) went further and prohibited them. I was told some years ago, by a deputy who had been in one of the rescue teams at William, that when his own pit closed and he transferred to Cannock he found a shotfirer charging a Cuckoo shot "because we've allus done it". 15 years on and still the lesson wasn't learnt - but my old friend soon put him right. There were few shotfirers in Cumberland, and Whitehaven in particular, who had a lax attitude to their job - we even had (and used) a break detector in a private mine which was not otherwise known for much in the way of compliance with Act or Regs.