I'm currently practicing for a show with my cello tuned down a half-step, and it strongly conflicts with my ear<->muscle memory. Similar experiences when jumping between standard tuning and the Bach 5th Suite (A string tuned down to G) or Kodaly Solo Sonata (lower two strings tuned down a half step).
That doesn't require perfect pitch. Most of the YouTube musicians noted for making videos of going on sites like Omegle and its successors and taking requests which they the then play perfectly after a short listen to the original if they don't know the song do not have perfect pitch for instance. Examples include The Dooo (guitar and piano), Frank Tedesco (piano), and Rob Scallon (violin).
There's also an element of violin-specific pitch detection; if you play violin for long enough, you can recognize the specific timbre of different notes on a violin (particularly easy for open strings) which helps ground you while listening to a tune.