I know exactly what you're talking about, I had the same question to when I saw this happen. Frieza slammed Goku into the ground and it seemed that he had died, as a quick cutscene to Gohan showed him crying because he couldn't sense his fathers life force, then the wish was made to restore everyone to life killed by Frieza and not to long after Goku surfaced from the rubble. It sure seemed to me like he had died and was revived back to life, but in reality he wasn't 1. because the wish was made by the Earth dragon who could not restore goku's life a second time, and 2. Goku was still weak and battered from his battle with Frieza, whereas other revived people (like Vegeta) were revived to full strength.

Goku didn't die then, he got into a ginyu force ship and went into an alien planet were he trained and learned instant-transmission

Nope. He crash landed on a planet called Yardrat, they taught him Instant Transmission. He flew back to Earth and then after Trunks killed Frieza and King Cold, Goku showed everyone Instant Transmission.

Yea I realized that after I wrote that :p

But my original post there's actually a lot of speculation about it

no, you don't understand, while goku was fighting frieza, Mr.Popo was gathering the Earth dragonballs so that they could wish everyone killed by Frieza back to life. After they did this Elder Guru was revived and with him Porunga who still had 1 wish to grant. That wish was to teleport everyone on Namek, except for frieza and goku, to Earth.

I never really got that though, Elder Guru wasn't killed, he just... died. He was just old. I didn't understand why he was brought back.

the reasoning behind it was that Guru's insufferable grief for the loss of his people (killed by frieza) caused him to die, they therefore concluded that Frieza was the driving force of Guru's cause of death, and when everyone killed by Frieza was revived he was included with them. I know it's a bullshit plot-fix, but whatever advances the story.

Oh wow. That's just stupid.