I’ve never liked the phrase. If an accused “gets off on a technicality” the prosecutor has failed to establish the case against the accused, who emerges without guilty verdict and is therefore innocent. So, when someone referring to a case being prepared by the Director of Public Prosecutions says that “every ‘i’ had to be dotted and ‘t’ crossed to ensure that nobody gets off on a technicality”, what they mean is that the evidence establishing guilt must be properly prepared. In this context, “technicality” is a synonym of “requirement of the law” and those requirements exist to protect the rights of citizens.
The phrase is so common that the perception exists that it can be easy to “get off on a technicality”. More often than not, it isn’t. Legislation creating a penal or taxation liability must be interpreted strictly (as held by the Supreme Court in Inspector of Taxes v. Kiernan  IR 117 3 ITR 19). A consequence of this is that legal requirements (“technicalities”) must be fulfilled. The thinking is that the Oireachtas has formulated rules and it is not for the judiciary to pick and choose which of those rules should be applied, thereby usurping the role of the Oireachtas. Given that criminal law involves the application of penalties a degree of precision is expected in formulating and applying the law.
The most common source of so-called technical defences is that of drunken driving (drug driving, now a common problem, is subject to similar rules). Mark de Blácam SC, in the introduction to his book on the topic, points to the disdainful tone often used when referring to technical defences. As already indicated, a “technicality” is a requirement of the law, but these requirements are often spoken of dismissively in the case of drink driving charges. de Blácam says:
There are many other crimes which are more heinous than drunken driving, yet one cannot imagine a judge deriding an argument as a “mere murder argument” or a “typical fraud point”. For whatever reason drunken driving has become associated with lines of defence which are sometimes fatuous, “often specious” and generally technical if only in the limited sense that they are not readily intelligible to the layman.
These “technical defences” have been a feature of the Irish criminal justice system for many decades, with the result that the technical requirements have been finessed and the Gardaí have had ample experience in ensuring all requirements are met. Therefore, the possibility of circumstances giving rise to someone “getting off on a technicality” are diminished. The popularity of the concept, however, is not and a “technical defence” is sometimes hoped for in other road traffic cases.
Take this example: an individual was reported by a member of the public for dangerous overtaking. The individual apparently admitted the offence but noted a minor variance in the details of the offence when formal notification was received. The individual then hoped to “get the low down on how to dodge points” so that (s)he might “get off on a technicality as the time is incorrect”.
The District Court Rules, which apply to most road traffic cases and other minor offences, provide that an error like this is not material for the purposes of the case. Nor is a difference between the location of the alleged offence as stated on a summons and that given in evidence at trial. The High Court has observed that “these provisions … were designed to discourage the taking of purely technical objections based on variations between the written detail of the complaint and the facts established in evidence” (DPP v. Winston  IEHC 275SS). Where there is a variance between the summons and the evidence, the judge can amend the summons and proceed to hear the case. Generally, one can only argue against the amendment of the summons where the initial error has prejudiced the accused or might affect the merits of the case. The judge can, in that situation, dismiss the case but can do so without prejudice to the charge being brought again. Therefore, the Gardaí can re-issue a corrected summons (once the time for doing so has not elapsed).
PS. Many road traffic offences are now detected automatically and dealt with by fixed charge notice. The notice will sometimes require correction through no fault of the Gardaí. For example, where an individual driving a car registered to his mother is detected speeding by an unmanned camera, the notice will issue to her as registered owner. The Fixed Charge Processing Office must be informed so that the notice can be reissued in the name of the driver. Failure to notify the FCPO frequently gives rise to summonses issuing. The Gardaí have a useful FAQ on fixed charge notices.