Crush injury with vascular spasm or transient vascular compromise: This is the most likely diagnosis given the blanched appearance of the finger after a crushing injury, despite good capillary refill and only slight numbness. The normal X-ray rules out a fracture, but vascular spasm or transient compromise could explain the symptoms.

Neuropraxia: The slight numbness could indicate a temporary nerve injury (neuropraxia) from the crushing force, which might resolve on its own.
Soft tissue injury: The symptoms could also be due to soft tissue damage (e.g., bruising, swelling) affecting nerve function or blood flow temporarily.
Compartment syndrome (early stages): Although less likely given the good capillary refill, early stages of compartment syndrome could present with similar symptoms before progressing to more severe signs.

Arterial injury or thrombosis: Despite the good capillary refill, an arterial injury could potentially lead to severe ischemia if not promptly addressed. This is less likely given the clinical presentation but is critical not to miss.
Infection (early signs): Especially if the wound is open, early signs of infection could be subtle and must be considered to prevent severe consequences.

Raynaud’s phenomenon (triggered by injury): Although rare, the crushing injury could potentially trigger an episode of Raynaud’s phenomenon in susceptible individuals, leading to vasospasm and the observed symptoms.
Complex regional pain syndrome (CRPS): This is a rare condition that can follow injury and is characterized by chronic pain, swelling, and changes in skin temperature and color. Early stages might present with subtle symptoms similar to those described.