Isn't there something in the rta about tenants making changes to the property - eg it's illegal to change locks or alter the property ?? Would putting up a cctv camera plus wiring on the external wall be an alteration?
Edit - Just found this. Does this apply:
16 (l) not alter or improve the dwelling without the written consent of the landlord which consent the landlord—........ may, in his or her discretion, withhold,
and would this apply also as an owner is obliged to comply with DP rules about cctv:
16 (b) ensure that no act or omission by the tenant results in there not being complied with the obligations of the landlord, under any enactment, in relation to the dwelling or the tenancy....
Can OP recharge the cctv company costs for removing the equipment from their property?