Problem with case statement and dynamic table name

I have the following case statement

case %1$s::text  when ''lookup_relation_job'' then    case %1$s.relation      when ''followers'' then ''get-followers''      when ''following'' then ''get-following''      when ''blocking'' then ''get-blocking''      when ''muting'' then ''get-muting''    end  when ''manage_list_members_job'' then    case %1$s.add      when true then ''add-list-member''      else ''remove-list-member''    end  when ''manage_relation_job'' then    case %1$s.relation      when ''follow'' then        case %1$s.add          when true then ''add-follow''          else ''remove-follow''        end      when ''block'' then        case %1$s.add          when true then ''add-block''          else ''remove-block''        end      when ''mute'' then        case %1$s.add          when true then ''add-mute''          else ''remove-mute''        end    endend

Here %1$s is an argument of type regclass.

When I run the above with %1$s = lookup_relation_job, Postgres throws an error saying: column lookup_relation_job.add does not exist. But it shouldn't even check for the add column when the argument is lookup_relation_job according to the case logic. What's going wrong here?

I suspect either there's some kind of fall-through happening here (I double checked that I've closed all case statements with end), or Postgres checks for all the conditions even if the parent condition is false (this is unlikely).

Any help would be appreciated!

Edit: Below is the whole relevant PL/pgSQL function

create or replace function get_jobs_to_add  (job_table regclass, active_jobs bigint[], failed_jobs bigint[], out result bigint[])  as $$beginexecute format('  select array(    select    distinct on (%1$s.user_id)    %1$s.id  from %1$s    left join user_profile on user_profile.id = %1$s.user_id    left join twitter_api_rate_limit on      twitter_api_rate_limit.user_twitter_id = user_profile.twitter_id and      twitter_api_rate_limit.endpoint = (        case %1$s::text          when ''lookup_relation_job'' then            case %1$s.relation              when ''followers'' then ''get-followers''              when ''following'' then ''get-following''              when ''blocking'' then ''get-blocking''              when ''muting'' then ''get-muting''            end          when ''manage_list_members_job'' then            case %1$s.add              when true then ''add-list-member''              else ''remove-list-member''            end          when ''manage_relation_job'' then            case %1$s.relation              when ''follow'' then                case %1$s.add                  when true then ''add-follow''                  else ''remove-follow''                end              when ''block'' then                case %1$s.add                  when true then ''add-block''                  else ''remove-block''                end              when ''mute'' then                case %1$s.add                  when true then ''add-mute''                  else ''remove-mute''                end            end        end      )  where %1$s.finished = false    and %1$s.paused = false    and %1$s.deleted = false    and (twitter_api_rate_limit.resets_at is null or twitter_api_rate_limit.resets_at < now())    and not (%1$s.id = any(%3$L))    and %1$s.user_id not in (      select user_id from %1$s where id = any(%2$L)    )  order by %1$s.user_id, %1$s.priority desc);', job_table, active_jobs, failed_jobs) into result;end$$ language plpgsql;