“I know this, Danny, but I'm just wondering why the question. If you refuse a breathyliser you'll be charged with drink driving as then it's assumed.”
No they would not, ummm. If you refuse a roadside breath test you will be arrested. At the police station you will be asked to provide an evidential sample (of either breath, blood or urine) for analysis. If you refuse you will be charged with failing to provide a specimen. They cannot charge you with drink driving (or at least with driving with alcohol or drugs over the prescribed limit) as they have no evidence of your alcohol or drug level. They may be able to charge you with driving under the influence of drink or drugs as no evidence of level is required. That charges relies on the level of impairment rather than the level of alcohol/drug concentration.