Jaime Maussan is not exactly what you'd call a credible source.
Look up Metepec creature (and not on the cryptid sites) And that's just one of the many hoaxes this man has perpetrated (or attempted to perpetrate). since 1970.
As for "showing it to Congress", he showed them (there were 2 alleged E.T. bodies) to some members of the House of Representatives (Cámara de Diputados) of one particular political party in a public audience,which is basically an open mic, and Maussan is friends with Sergio Gutiérrez Luna, who previously was the Speaker of the House, who too it upon himself to promote the video; so....