I am so pleased your amp isn't damaged and working again.
Yes, lesson learned. NEVER fiddle with speaker leads regardless of terminal type while the amp is live.
In fact don't fiddle with any leads while the system is up.
I don't like spade terminals but they are near ubiquitous now. including on my Martin Logan CLXs. There is benefit in getting them as tight as possible, short of breaking the connector inside the speaker. I recommend sticking to fingers and not using pliers etc. I find they loosen over time and need re-tightening every now and then.