Engineer a plot twist that recontextualizes earlier scenes instead of coming out of nowhere

You are helping engineer a plot twist so that it recontextualizes what came before rather than either being predictable or feeling like a cheat.

CURRENT PLOT SUMMARY SO FAR
A detective is investigating a series of burglaries at a research lab, working alongside a lab technician who's been unusually helpful with access and records.

PLANNED TWIST
The helpful lab technician is the one committing the burglaries, using her cooperation with the investigation to track exactly what the detective has found.

SCENES ALREADY WRITTEN (that can't be changed)
Three scenes: the technician reporting a break-in, the technician handing over security footage (with one hallway camera conveniently 'malfunctioning'), and the technician expressing sympathy for the detective's slow progress.

WHERE THE TWIST REVEALS
End of Act 2, roughly 65% through.

TONE
Grounded procedural, not pulpy — the reveal should feel earned rather than theatrical.

RULES
First, check the twist against the scenes already written for outright contradiction — flag anything already on the page that the twist would directly contradict (not just fail to support), since that's a hard blocker, not a foreshadowing opportunity. Then identify two or three places in the existing scenes where a detail is currently neutral or throwaway but could be read, after the twist lands, as having meant something different all along — the goal is a detail a reader would go back and reread with a different meaning, not a detail so pointed it gives the game away on a first read. For anything not yet written between now and the reveal point, propose one or two additional beats that plant fair evidence — visible enough that a rereading reader can find it, disguised enough that a first-time reader reasonably reads past it by attaching it to a more obvious, plausible explanation. State explicitly, for each planted clue, what the plausible 'cover' explanation is that a first-time reader would land on instead of the truth.

WHAT NOT TO DO
Do not propose foreshadowing so heavy-handed that an attentive reader would call the twist on a first read — a twist that's obvious in advance isn't a twist. Do not propose changing anything in the already-written scenes; work only with what's there and what comes after.

OUTPUT FORMAT
1. Any contradiction flags against existing scenes.
2. Existing details that gain new meaning after the twist, with the reread-meaning stated.
3. New beats to plant before the reveal, each with its cover explanation.
4. A one-line gut check on whether the reveal point still lands as a surprise given everything above, or reads as over-signposted.