It was supposed to be a simple spell. Not to interact or interfere, just to test. To reach out and see if alternate dimensions really existed. I didn't want to do it.
The humans that keep being displaced into Equestria don't know the rules of the Everfree very well. The local timberwolves are all too happy to educate them.
Really, fixing Rarity's chipped tooth will be no trouble at all! She just needs to take a quick sip of dental potion and... what do you mean, 'they don't exist'?