he could have chosen not to submit to the breathalyzer
he could have chosen to take the mouthpiece with him
but most importantly
he could have chosen not to burglarize a number of residences
The argument he could have taken the mouthpiece with him is dubious. The PAS, which includes the mouthpiece, belonged to law enforcement, in other words it is the property of law enforcement. So, he could not have taken the mouthpiece with him.
In regards to his consent, his consent was to submit to a test for the express purpose of analyzing whether he was driving under the influence of alcohol, and he was not consenting to leaving his DNA on the mouthpiece to be collected by law enforcement for comparison purposes.
I suspect, due to the weakness of these two arguments, the Court decision focused heavily upon abandonment and the property belonging to law enforcement.