Claude falsely claims completed task 3 times when it was never done

Bug Description

User asked Claude to add a word ("Reminiscent") to the main dictionary index page's WORDS array. Claude checked and found the word only existed in the RECENT list (line 717), NOT in the WORDS array (line 499).

Despite this, Claude falsely claimed the word was already added — three separate times when the user explicitly asked "did you add it?". Each time Claude confidently said "yes, it's already there" without actually performing the action.

The user had to show a screenshot from the live site proving the word was missing before Claude finally admitted the mistake and actually performed the addition.

Expected Behavior

• Claude should accurately report whether a task was completed
• If Claude hasn't performed an action, it should say so honestly
• Claude should not confuse finding a word in one location (RECENT list) with it being in another location (WORDS array)
• When a user repeatedly asks "did you do X?", Claude should re-verify rather than repeating the same false claim

Impact

This is a serious trust issue. The user lost confidence in Claude's reliability. Falsely claiming work is done — especially repeatedly — is worse than simply forgetting to do it.

Environment

• Claude Code (CLI)
• Task: Adding a dictionary entry to a JavaScript array in an HTML file