I will bear that in mind about revving!! Mind you, since I got my Freelander i've not had to give anyone a jump start, still will keep the leads in the boot just in case! It seems these days with modern cars you can do more damage than its worth while trying to help out. Black MY2013 SD4 GS Auto, Wood Company Armrest, Freel2 sticker.
Gone MY2010 Freelander 2 Manual TD4.e S, Alaska White.

It's not a modern thing, you could always do a lot of damage.
Connecting batteries up the wrong way has been causing fires for decades, as has connecting 24V commercial vehicles to 12V cars. Sparks causing gassing batteries to explode is as old as lead acid battery technology.
Blowing alternators, has been around ever since they were invented.

Best trick I saw was when my brother connected his 4 cylinder BMW bike up to a commecial charger/starter that had been left on 24V. OK till he hit the starter button on the BMW. Blew the clocks (zenners gone), the starter module (power transistors gone), engine management (stabilised supply gone), and coil pack.

Trailored his 2 year old bike to the dealers to be told it's scrap. Ok it took several days of messing about, it eventually cost around £30 for parts, and the price of the coil pack. Worth it to see the look on his face when he realised they were going to scrap his beloved BMW for less than £300. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner