Yes, if the stakes were large enough, & the adversary sufficiently skilled/resourced, it is possible an impersonator could also intercept & redirect your call t

Yes, if the stakes were large enough, & the adversary sufficiently skilled/resourced, it is possible an impersonator could also intercept & redirect your call to "the police" – for example by compromising phone network systems or the police-department's switchboard. (Or, somehow corrupt your usual means of looking up that police number.)