When the target gets affected by any sort of instant movement (teleports, but also stuff like reality rift, x mark and glimpse), the lasso breaks, regardless of how far the spell moved it. So even a 0 range glimpse breaks the lasso.

1. Lasso an enemy
2.1. Have an allied or enemy Kunkka cast X Mark on the same enemy and immediately cast the Return sub-spell
2.2. Have an allied Magnus hit the target with Reverse polarity
2.3. Have an allied Chaos Knight cast Reality Rift on the target
2.4. Have an allied Disruptor cast Glimpse on the target
2.5. Have an allied or enemy Vengeful Spirit cast Nether Swap on the target from very close

Result: The laso breaks, regardless of how far the target gets moved by the spells.

Expected: The lasso should only break when these spells move the target more than 425 range away from Batrider.

This goes for every teleporting effect. The 4 listed ones are just examples. The same applies to all Blinks, Test of Faith tp, Kotl recall, poof, morph replicate, earth splitter, furion tp, phantom strike, doppelganger, ethereal jaunt, blink strike, burrowstrike, spectre reality, spirit bear return, nether strike, tp boots/scrolls, dark rift and time lapse.