I agree with your interpretation of the spec. Therefore, for interceptor methods (be it lifecycle event callbacks or not) defined on interceptor classes we should not probably check the throws clause. What I propose to check for interceptor methods defined on an interceptor classes is:

• return type
• parameters

and throw a definition exception if validation fails

For target class lifecycle event callbacks I propose:

• log a warning if the throws clause is specified (as it should not be according to the spec)
• and throw a definition exception if:
  • return type is wrong
  • parameters are wrong