cogliere sul fatto significa in inglese

catch out▼(to discover or expose as fake, insincere, or inaccurate)
verb
[UK: kætʃ ˈaʊt] [US: ˈkætʃ ˈaʊt]

catch red-handed▼(capture someone in the act of committing a crime)
verb
[UK: kætʃ red ˈhæn.dɪd] [US: ˈkætʃ ˈred ˈhæn.dəd]