Subscriber can change state of work ticket though person doesn't belong to category of that WT

Hi  All,

 I have seen cases where subscriber  can modify and change state of work ticket though he is not part of that team area and category too. and agian he cant do few actions in that WT.

 We have set of roles defined, Lead, approver, member. while modifying WT, RTC will consider role assigned to user in that Team area ,which WT belongs to.

subscriber has default role at project area level and has few(member) roles in other Team area.

So I am not undestanding which role is allowing  the subscriber to modify WT

( default role in project area or member role in other team area)?

Thanks,

Kavita