The global "Case sensitive check" option (Policy->Options->Pattern Matching Options) applies only to pattern matching expressions.
When the "Operator" is set to any other value, for example to "equals" instead of "matches", the "Case sensitive check" setting will not apply to this condition.
Once the "Operator" is switched to "matches", pattern matching will be performed and the global "Case sensitive check" flag will be considered.
It is also possible to separately adjust the case sensitivity for every condition with operator "matches".
When a "matches" operator is selected in the right end of "Operand" field an arrow appears, that gives access to an additional window with "Pattern Matching Expressions" and "Variable Binding Options" containing the local "Case sensitive check" option (enabled by default).
The same is true for all Event policies where the "Operator" can be selected - XML File, Log File and Database Policy.