Thats the thing, I dont think he was making that choice based off of the safety of his ship or crew. He became panicy and was trying to save his own skin first and foremost.
Was it a good call by a military standpoint? Maybe. However with the lack of any intel on his part going back to Earth would have been fruitless as a warning. What is he going to warn them about? A glowing bubble caused his ship to crash and then they managed to get off planet? The only thing they had intel on is the Prometheans, and even that was just a confermation that they exist. No threat analisis. No known intent that the Prometheans might have had.
The call to remove Cortana from the ships systems was the right one. That much I wont debate, but the lack of composure on his part over the course of the game shows that he is cracking under the stress of a combat command and is not making rational choices for the safety of his crew. The "blow through op" was completely unnessissary. He put lives at risk with no intel and lost equipment and men in the process when there was no need to do so. A force recon would have found out how heavily defended the area was and saved lives. He made a really bad call and got people killed and just brushed it off like it was nothing.
His lack of composure and poor choices in his mission prep, lack of intel on the new enemy as well as the lack of trust and support from the crew (remember Palmer did not want him in command nor did many others) really shows that he cracked and was looking out for himself, not the ship or crew. That is a huge problem with me.
As for proof, one would think that all they would have to do is check John's battle cam to get visual evidence of the existance of the Didact however Rio didnt even consider this... Again poor judgement.