Not everyone knows that query level hints (like loop join) will impact the entirety of a DML query plan. This includes foreign key validation and indexed view maintenance.
Let us look at an example with two tables involved in a foreign key constraint.
use tempdb
go
create table department(deptid int primary key clustered, deptname varchar(10))
go
create table employee(empid int primary key clustered, empname varchar(10), deptid int references department(deptid))
go
insert department values(1, 'Optimizer')
go