Continuity: Outgoing = Incoming Seal
Tip 39: The key to usefulness of alphanumeric seals on a #duisimulator is whether or not the incoming seal number on the subsequent solution change date equals the outgoing seal number on the prior solution change date. If the incoming seal number does not match the outgoing seal number, then an inference can be drawn that someone broke the seal and replaced the seal between those two dates. If someone broke the seal, then an inference can be drawn that they, or someone else, changed the alcohol standard, that was placed in the simulator on the prior solution change date. Since all, not some, alcohol standard changes are supposed to be recorded in the Alcohol Standard Log (see CFS Training Aid Appendix "E") the inference of an unrecorded alcohol standard change should be some evidence of operator error.
In the case of R. v. S. at Orangeville, the Alcohol Standard Log was made an exhibit:
The subject tests were conducted on June 20, 2009 and the Crown alleged that the alcohol standard had been changed on June 9, 2009. Notice that the outgoing seal number on June 9 "558351" does not match the incoming simulator seal on June 21, 2009 "20669". Shortly after cross-examination by defence of the Crown expert, on this issue and on the length of time between June 9, 2009 and June 20, 2009, the matter was resolved under the Highway Traffic Act.
Defence counsel need to be aware that not all alcohol standard solution changes occur on a one week or two week cycle. Unscheduled alcohol standard changes can occur for several reasons. Please see page 83 of 238 of the 2013 CFS Training Aid.
The Defence needs to know if anyone has tampered with the alcohol standard solution between the prior solution change and the second (or third) subject test. The Defence needs to know if there has been an unscheduled solution change for one of the reasons stated above. The unredacted Alcohol Standard Log should reveal that information if the Log has been kept in accordance with Appendix "E" of the CFS Training Aid.
I respectfully suggest that any redaction by the local Crown's office of the log entry for the subsequent solution change date will interfere with full answer and defence. I also respectfully suggest that failure of a police service to properly log outgoing and incoming seal numbers will also interfere with full answer and defence and should be considered as (systemic) operator error.