You cant really evaluate technique without working directly with the singer.

He sang somewhat high. Any issue like poorly adjusted support, lack of forward placement or simply not having resources to protect his voice when things are not going fine could lead to trauma.

Not managing his vocal health well could also lead to it (not enough rest, hydration, etc). Most likely a combination of factors.

Its easy to, similar like people did with Adele, to come NOW and say "I knew it was going to happen"...

hehe yeah, but Ive already seen comments relating it to some kind of distortion he did sometimes, or the otherway around, saying that it was all good and it was just due to workload (which as you mentioned, was not sooo heavy and would not justify surgery).

More aggressive singing rises the risk for damage, I dont think its possible to deny this. But, without good technique, aggressive or not you are really begging for it to happen and at a much greater risk (its out of your control).

Check the performances of Edu Falaschi on Rock in Rio 2011, in special Rebirth. This is a guy that used to make it look all easy and effortless too...

When it comes to the mid-high range, there are some traps you can set for yourself, like believing that transitioning registers early will save your voice, or that if you try to reduce effort you will be more economic. Both can lead to strain and increasing collision force.

The most "vanilla" thing you can do about that area thinking of health preservation is covered full voice, and you need quite some physical effort to do it.

@Owen thats one of the many things he said about his problems along time (they go WAY back, it was not just one show), and frankly the only thing that changed is that he is not on Angra anymore. Ive came across the results on his students too... Scary stuff...

@killer haha that would fit more Dave Grohl ;).

@Owen hahaha awesome

And to give some food for thought, here is a guy who had a quite demanding repertoire to handle, and as you can hear on the early performances problems to execute (although always with technical awareness):

http://www.youtube.com/watch?v.....h2rNd1YoKY

http://www.youtube.com/watch?v.....TMiYyxl7CA

http://www.youtube.com/watch?v.....OvCPJGjaiE

Age, 26, 41 and 51 respectively

You don´t need to destroy your voice because of demand, you just need to know what you are doing :). And although perfection is not possible, getting to the point of surgery is plain bizarre, sorry.

Funny you mention that guy with the allergy Owen, because the past week I had completely lost my voice and intuitively worked out it was an allergy, I cut out the food and my voice has now returned back to normal again. Good thing too because I have a performance in 2 weeks and was worried I was not going to be able to practice for it.