Emergency service personnel receive extensive training on response driving (lights & sirens). If I respond to a call of a burglary I am automatically allowed to exceed the speed limit by 30mph (50kph?), going faster than that it is up to me to justify.
How much do those sky-lifts weigh? I'd imagine 5 tonnes or so - either way they're not particularly manoeuvrable.
When responding to a call the driver has to drive with 'appropriate speed'. In the first situation the road was fairly clear, with good road conditions so the driver could justify the speed. Nonetheless it was somewhat careless to go round a corner and veer onto the wrong side of the road - you're going to help people, why kill someone on the way?
The second can't be justified. What that driver of the sky-lift did, in my eyes, was entirely illegal (in UK response law/guidelines anyway). Approaching a junction you should reduce speed so you can stop if you have to. The junction the truck went through was congested and busy making it even more dangerous.
Ultimately, it's up to the driver of the emergency vehicle to make decisions on speed - in such a high pressure situation it's easy to make the wrong decision.
EDIT: All of this relates to UK law, US State will probably be different.