Per the OP's request, we should keep this scientific.
Would anyone have data of a RadAlt overflying a location with a Sasquatch below the aircraft; then a second flight (over same area) without Sasquatch. We must have proper test and control groups.
Does the said sasquatch have a 5G mobile phone?
Is he wearing a tinfoil hat? (Can interfere with all the electromagnetical fairies)