If one cannot remove it with hand tools, it was too tight. There is specific torque value lugnuts needs to be tightened, and that torque is well within what hand tools should be capable of. Our cars in boot have stock lugnut wrench (for changing to spare emergencies), which should provide very aproximated somewhat right torque, due which it is of specific length(lever length). At least if one uses tube over that wrench for longer lever, that would be "overtightening with hand tools"
.. some googling for torque value returned:
Manual reference number: AIM 004 425 - 4 https://www.toyota-tech.eu/Aim/Aim2.aspx?pubtype=AIM&menuitem=1 https://www.toyota-tech.eu/aimuploads/9001c475-3fa4-4bb5-994d-86f55a1f54d2/Torque_values_for_Alloy_wheels_Steel_wheels_Wheel_lock_Toyota_AIM_004_425_4.pdf
GT86 Mar'12- Wheel Nut Torque (N*m): 120 TPMS/TWMS Torque (N*m) 4
For aluminum aftermarket lugnuts it might be less, who knows.
I don't think that some water getting in might be at fault. Exactly for that these are -closed-end-lugnuts-. Now sloppy tire tech that cluelessly impact overtightened imho is much more possible :).