Cannot UNNEST null array fields

[ohaibbq]

WITH file AS (
  SELECT 1 AS file_id, ARRAY<STRING>["r", "w"] AS modes
  UNION ALL SELECT 2, ARRAY<STRING>["w"]
)
SELECT id,
(SELECT mode FROM UNNEST(modes) AS mode WHERE mode = 'w') IS NOT NULL AS write_mode,
(SELECT mode FROM UNNEST(modes) AS mode WHERE mode = 'r') IS NOT NULL AS read_mode
FROM UNNEST([1, 2, 3]) id
LEFT JOIN file on file.file_id = id

Expected

id	write_mode	read_mode
1	true	true
2	true	false
3	false	false

Actual

id	write_mode	read_mode
1	true	true
2	true	false

panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x70 pc=0x100ee1d94]