Characters
(Eddie is arrested for stealing a case of wine) Patsy: My name is Patsy Stone and I am an alcoholic, and what she did was an act of humanitarian mercy.
— Patsy · Absolutely Fabulous

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Speaking in the first person, the speaker announces an alcoholic identity and then calls what another person did an act of humanitarian mercy. The brazen framing turns a wine theft arrest, as noted in the stage direction, into charity, with the confession serving as comic justification.
Context reviewed