Whether or not you are found guilty at a trial will depend on whether the crown attorney can prove a guilty act and a guilty mind.
In order to prove guilt, the crown must prove two parts for every criminal offence. The crown must prove an act (actus reus) was committed by you and that you had the criminal mental intention (mens rea) to commit the act. There is no guilty act without a guilty mind.
To prove the guilty act, the crown has to show:
a) an action (or omission of an action)
b) by a person with capacity
c) in a voluntary manner
d) which caused certain consequences.
If there is any reasonable doubt about whether these aspects of the alleged criminal act occurred, the court must find you not guilty. You do not need to testify and your lawyer does not have to prove that the alleged criminal act did not occur. You can remain totally silent because the burden of proof is on the crown.