The only way that I can duplicate this behavior is to request the value(s) of the parameter in list context:

my @value = $q->param("bloption");
[download]

Otherwise, CGI.pm returns a scalar with the value of bloption. Examining the URL of the submitted form (that contains the two submit buttons), I can see that only one value for bloption is actually being submitted:

http://localhost/~sutch/test/index.cgi?bloption=add
[download]