The variance in temp is too slight, wouldn't make a difference. The SG is very important. At 25% it could change parameters enough to stress coral. All depends on what the actual SG of your new water was. If it was close, like only .001 - .003 difference, I'd say no big deal. But if you were talking about a difference of >.005 then you might have some concerns. However, I still wouldn't think it would be enough to kill a coral. Stress it, yes, but recoverable.
Now if you forgot to add salt to your makeup water, and accidentally removed 25% SW and added back 25% FW, IMO that could do some damage.
I've never used Chemi-Clean, so I don't know what that would do.
swimmer