With all due respect to your adjuster friend (who may well be correct), you would best serve your client by submitting the claim and letting the company either accept or reject. If you don't, you leave yourself exposed to possible error/omission claim from your friend in the event the company may have accepted the claim.
For what it's worth, if the only damage it to the vehicle caused when the wheel impacted it, you appear to have a collision: the car collided with the wheel. Or, if you prefer, the wheel collided with the car. Either way, it appears to be a collision.