[rules-users] Ignoring PatternSyntaxException in decison tables

Hello, we have provided users with option to edit some of the rules in Excel table. One of the CONDITIONs uses "matches" operator and the pattern is in the spreadsheet. Users have entered wrong regular expression which, when compiled using Pattern.compile(), throws PatternSyntaxException. The rules defined in the Excel table are however loaded and merged into the knowledgebase without problems. At runtime during evaluation no error is thrown. My question is: Is there a way to find out wrong regular expression on the RHS of matches operator during knowledgebase creation? Ales