Why was dr schulz's caution his undoing in mrs frisby and the Rats of NIMH?

Dr. Schultz's caution was his undoing because it made him hesitant to fully trust Mrs. Frisby and the rats of NIMH, which resulted in him missing out on the opportunity to collaborate with them. His cautious nature ultimately led him to underestimate their abilities and intentions, causing him to make decisions that were not in his best interest.