Ok - got this SPROC

Code:
Create Procedure awc_PartGeneral_Add @Part varchar(100), @username varchar(100)--@SQLGuid varchar(36)
As
Set NoCount On
Declare @ND datetime
Declare @Seq int
Declare @NoteKey varchar(100)
Declare @SK varchar(100)
Set @ND=Convert(varchar(10),GetDate(), 101)
Set @Seq=IsNull((Select Max(Seq) From PartNotes_T Where PartId=@Part and NoteDate=@ND),0)+1
Insert into PartNotes_T values (@Part			-- PartId
			,@ND			-- NoteDate
			,@Seq			-- Seq
			,'N'			-- Face
			,15			-- TimeSpent
			,@username		-- AddedBy
			,''			-- ContactType
			,'OtherPhone'		-- MetWhere
			,''			-- MetWith
			,''			-- Note
			,GetDate()		-- TDate
			,'N'			-- Conservator
			)
Set @NoteKey=Scope_Identity()
Set @SK='~save~'+@NoteKey
Select	 '["save","add","undo"]'		"buttons"
	,'{"focus": "NoteDate"}'		"awcoptions"
Exec awc_PartGeneral_Edit @Part,@SK
and as you see I have no BEGIN TRAN and COMMIT...

I kind of always thought a SPROC was automatically contained in a TRANSACTION.

But it seems that two different users were maintaining the same "participant" and adding a note - and the SEQ number passed back to the UI was the "same" for both users.

I can only think that the Set @Seq=... is grabbing the same number because the INSERT had not happened yet - and that's only possible if the each SPROC line is not in a transaction.

Part of me does not want to believe the user - but they are saying it happened although not with enough technical info to be really firm.

I'm not sure how to even try to replicate the problem so I can see it really happen and then prove I fixed it...