Sure, not every runtime type error needs to panic your application, nor even panic a request handler, nor even result in a failed handling. That doesn't mean you didn't encounter an error though. Error doesn't mean fatal.

The design decision isn't, "Was this a type error?" but, "What do I need to do about this type error?"

“BRITANNUS (shocked). Caesar, this is a type error.

THEODOTUS (outraged). How!

CAESAR (recovering his self-possession). Pardon him. Theodotus: he is a barbarian, and thinks that the customs of his tribe and island are the definition of the float type.”