The scale of {ba'a} always refers to an experience.
Either in the expected future, the present or the past.
{ti'e} on the other hand tags an utterance as hearsay, possibly
with a focus on the uncertain truth value of the statement.
{ti'enai} then implies "grounded" knowledge pe'i.
So (pe'i) it would be reasonable to say {ti'enai li pa li pa te sumji li re},
whereas the same sentence tagged with {ba'anai} sounds weird.