Yeah, cameras have built in IR filters that block pretty much all IR contamination in normal conditions, but in situations where visible light is blocked or filtered out but IR light is passed freely then the proportion of IR to visible is raised to the point where it can cause muddy colors. I.E., the tree canopy filters visible light so you increase exposure, but IR isn’t filtered out by the trees and so you end up with more IR exposure than you normally would. The same thing can happen with neutral density filters. Traditional ND filters block visible light, but freely pass IR. So when you increase exposure to compensate for the ND you dramatically increase IR.
Here’s an extreme example showing a normal shot, a shot with a dense traditional ND filter, and a shot with an IR blocking ND filter. Video cameras are usually more susceptible than still cameras, but it still happens, just not as bad as this usually.