Are transparent neon Lego bricks made from a different plastic than usual?
All of this is correct, ABS can't be transparent and thus transparent parts are made of PC.
PC against PC bonds way too tighly and designers are actually forbidden to do that in their models. (I've a 4L lightsaber blade stuck in the crossend of a Technic beam, both trans-red, and I can't get it out.)

I'm fairly sure there's a designer (possibly Jamie Berard indeed) presentation on things forbidden to designers but I can't find it back.

Edit: @Grandpappy found it back: http://bramlambrecht.com/tmp/jamieberard-brickstress-bf06.pdf and it's indeed by Jamie Berard. Worth reading again and again.