Theoretically it could possibly mean that, but it would require some really unusual context for the two parts to have separate time contexts. At some point we contributors have to decide that we have reached our limit on reasonable alternative translations. If you put both sentences in the present tense, that will be accepted. And if you put both sentences in the past tense, that will be accepted. But if you put one sentence in the past and one in the present, then it will not be accepted.
Are you saying it was a tile exercise and you didn't have the correct words?
It seems like Duolingo picked a past tense version for you. If you had just switched "see" and "saw" it would have been correct. "We saw Mara but we did not see Torg" would have had both sentences in the past tense.
Remember that when you use "do" in English, "do" conjugates for person and tense and the main verb should be in the infinitive. It is not correct English to say, "did not saw". You have to say "did not see".
I tried "We can see Mara but we can't see Torg", because there was no context for tense that I could tell. ...laH. It would have been correct if it was wIleghlaH/wIleghlaHbe', but it's not, so it's not a statement of wherer or not we can but whether or not we do/did.
The prefixes and suffixes are driving me mad XD
It's a different way to think about it, so it takes a while to get used to it. wIlegh can be "we saw her", "we see her", or "we will see her", but you have to add -laH to get "we could see her", "we can see her", or "we will be able to see her." It takes a while for English speakers to get used to that.