Final answer:
The query 'But before all that, I had double checked my reservation?' refers to the use of past perfect tense in English to indicate that the speaker confirmed their reservation before other past events.
Step-by-step explanation:
The sentence 'But before all that, I had double checked my reservation?' is an example of using the past perfect tense in English. The past perfect is used to describe an action that was completed before another past action. Here, the speaker had confirmed their reservation before proceeding with other actions mentioned in this context. The content loaded within the given snippets indicates a narrative where detailed planning, investigation, and unforeseen issues in legal and personal matters are central themes.
The past perfect tense construction 'had double checked' serves to show the sequence of events, which is a common aspect of storytelling or recounting incidents. Ensuring facts like a hotel reservation were verified before an event signifies the character's diligence or the importance of the subsequent actions.