ANY or IF EXISTS in T-SQL

Question

I have a table which is a mapping between foreign ids and local ids.

I had to write a query to find out whether or not this table is a bijection. I came up with this

IF 1 <> ANY(
    SELECT COUNT(foreignId)
    FROM mappingTable
    GROUP BY localId
    )
BEGIN
    SELECT 'Oh noes!'
END

ELSE BEGIN
    SELECT 'Everything is fine.'
END

My supervisor took one look at this and grimaced, and told me I should have written this instead:

IF EXISTS(
    SELECT NULL
    FROM mappingTable
    GROUP BY localId
    HAVING COUNT(foreignId) <> 1
    )
BEGIN
    SELECT 'Oh noes!'
END

ELSE BEGIN
    SELECT 'Everything is fine.'
END

My question is simply which of these queries is better style. I'm pretty sure that they are equivalent.