  It is often said that there is no gravity theory based on local action
principles giving rise to firewall black hole solutions. Additionally, Guo and
Mathur 2022 (2205.10921) have cast doubt on the observability of firewall
echoes due to closed trapped surface produced by backreaction of macroscopic
in-falling wave packets. In this paper, we bring Einstein-Maxwell-Dilaton
action as a toy model that serves as counterexample to these assertions.
Actions with Maxwell and dilaton fields emerge from several fundamental
theories, such as the low energy limit of (super) string theory or Kaluza-Klein
compactifications. In these systems, the black hole solution has two curvature
singularities. We will show that the outer singularity inside the event horizon
can cause significant change to the outside, close to the extremal limit,
making a macroscopic reflective barrier near the event horizon that would lead
to "observable" gravitational wave echoes in this toy model. Additionally, we
also call into question the argument by Guo et al. 2017 (1711.01617) claiming
that a very small fraction of the backscattered photons will be able to escape
back to infinity from the firewall using these black holes as counterexample.
