The session
We just arrived in a village and one of our member got ill and puked in the inn, so we went to the village doctor for help and he told us to go to continent Y where they could know how to heal the illness. Unfortunately the priest of the villager had learned that we were ill so he wanted to burn us. As the doctor hid us and was brought to the stake, we decided to help him by undermining the priest's autority. Thanks to a perfect roll we told the villagers the priest was the one corrupted, so the villagers released the doctor and wanted to burn the "corrupted" priest (who ran away). However, since we were ill, they still wanted to burn us, so we flew and ran for 2 hours and then walked for some hours before stopping to camp.
The GM told us it was night and we were in some fields with a village in sight. A bit later he told us there were torches coming our way from the village, so I asked how many of them were coming and he told us there were two torches. We decided to stay here and see what the villagers wanted from us. A bit later the GM told us they bumped into us because we were in fact near tall wheat so we didn't see them coming at the end and both the villagers and us were surprised.
He didn't told us there was tall wheat near us and that we stopped seeing them (and how could have we seen the torches if the village was hidden by the wheat in the first place?). Anyway, then the villager asked us what we were doing here and if we could leave, and then he dramatically described the priest coming out of the wheat with some archers and telling us "We meet again," and that was the end of the session.
My thoughts
I understand that he wanted to finish the session dramatically and maybe cause a battle since we didn't have one since the beginning of the session, but I personally feel like I've been cheated because there were important elements that were hid from us and that the GM only wanted to make his plot no matter what. I'm wondering if it's common practice, if it's our fault for not asking or if it is the GM's for not telling us important elements.
For example if I knew there was tall grass and we couldn't see the villagers approaching, I would have probably suggested running away so that we couldn't risk an ambush. I didn't constantly asked if we were still seeing them or asked how many of them there was if we could now see them under the light of the torches.
I thought that was obvious that we were still seeing them as there wasn't any change to the narration, but now I'm wondering if it's really the case. I'm now wondering for the next session: Should I ask meaningless questions all the time in case an important element escape from us? I'm afraid that this would be boring for me, the GM and the other players, and I'd like to know how to deal with this kind of situation.
I've only done a dozen sessions of RPG so I'm not very experimented, but that's the first time I feel fooled by the GM like this. I didn't bring this to him (yet) as I know he doesn't like to have his GM techniques called into question. (e.g. asking him during the session "But you didn't told us there was tall wheat on their way to come to us, I thought we were having a clear view of the village?")
Maybe it's just a lack of experience and I should have asked "Do we have a clear view of them all the way to us?", "Do we still see them?", "Do we have a clear view of our surroundings?", instead of just "How much of them are there?". It's not exactly the first time it happened with him but I never had this problem with other GMs (they told us obvious things like "someone is approaching you in the street-", maybe make us roll the dice before, and not tell us directly "someone has approached you while you were talking and he attacks you" because we should have asked "is someone coming our way?") so I feel like it's a bit odd to me. I don't want to mistrust everything the GM is telling us and other than that he's a great GM who wants to push us to take decisions quickly and have dynamic sessions.
How much should I put into question what he says and ask additional questions?