e.g.

declare @1 table (a int, b int)
declare @2 table (a INT, b int)

SELECT a, b FROM
@1 a
CROSS JOIN @2 b

Here there are 2 possibilities for columns a and b, however SQL prompt only suggests the second one. Both should be shown and the user given the chance to choose.

SQL Prompt does not recognize the ambiguity nor alert the user to it (although Microsoft Intellisense does flag the ambiguity). This can result in the user selecting the wrong alias (since only one is presented, apparently the last one found) which can result in hard-to-debug incorrect results.