It would cause Google to have a relatively larger proportion of "difficult" searches. Many "difficult" searches on Bing will be repeated on Google, but not the reverse.
If you assume that all "difficult" searches fail on both engines as a first approximation, that would mean that Google will fail all the "difficult" searches, while Bing will only fail the "difficult" searches made by people who primarily use Bing.
If you assume that all "difficult" searches fail on both engines as a first approximation, that would mean that Google will fail all the "difficult" searches, while Bing will only fail the "difficult" searches made by people who primarily use Bing.