Yaarel
🇮🇱 🇺🇦 He-Mage
OK, so this is clearly not the way the language makes sense. I have three arguments:
1)"... and unless you shift your attention to another creature’s thoughts, the creature can use its action on its turn to make an Intelligence check contested by your Intelligence check; if it succeeds, the spell ends." -
PHB p233. Meaning if you only do a surface scan, the target doesn't get a chance to end it with an intelligence check.
2) "Unless a spell has a perceptible effect, a creature might not know it was targeted by a spell at all. An effect like crackling lightning is obvious, but a more subtle effect, such as an attempt to read a creature’s thoughts, typically goes unnoticed, unless a spell says otherwise." - PHB p204
3)https://rpg.stackexchange.com/quest...-the-target-aware-when-not-doing-a-deep-probe
Where you will find a more detailed discussion of the wording, but the general consensus is similar to my interpretation.
But it is impossible to 1) ‘shift your attention to an other creature’, if a successful Wisdom save has already ended the spell.
‘Either way’ can only mean two ways in which the spell is still active: a ‘surface’ probe that is still active, or a ‘deep’ probe that is still active. The target can attempt to end the spell with an Intelligence check, either way, unless shifting away to an other target.
If shifting away, the old target can no longer attempt to end the spell with an Intelligence action. But of course, the new target can attempt to do so.