Making things up.

[achre]

Well, not exactly "making things up", but...
If you're writing about a particular topic for an essay or an extended response question or w/e, how damaging is it to state something that likely happened without being 100% sure that the thing actually happened?
I was doing a practice exam yesterday, and I didn't study 'cos I had other exams on, so I couldn't recall the exact figure of how much money China spent on the construction of a stadium for Costa Rica. I said $500 million, checked later, it was ~$100 million (plus 800 Chinese labourers).
I also had a friend who told me that for some issue, he said (for some case study, I forget which) that France condemned the action, which he claimed probably happened, though he had no idea whether or not it actually happened - i.e. it could be complete fiction.
What I want to know is, can you get away with making up statistics and responses, provided they're within reason? Do the assessors have google open while marking, fact checking every statement you make? And furthermore, how damaging would it be if you were found out? Would they assume you misremembered, or would it be worse than that?
Obviously this isn't ideal and won't likely happen on the actual day, but I'd like to have some idea... just in case.

[TonyEcon]

It won't damage your score at all. So long as it isn't ridiculously wrong.

[mattbrown19]

It won't damage your score at all. So long as it isn't ridiculously wrong.

Is that how you got your 50? :p

[charmanderp]

Like Tony said, so long as it's relatively close to reality to the extent that it provides more or less the same degree of support to your argument, you'll be fine.