Well, shipping did break the sealed part of a sealed battery, so it is their fault. I wouldn't keep it. It's not sealed. They may go "It was hazmat." and pull a fine on you, but under DOT-CFR Title 49 parts 171-189 it is classified as non-hazardous.
One specific part is here:
(d) Conditions and requirements specific to certain materials . Hazardous materials offered for transportation or transported in accordance with the ICAO Technical Instructions must conform to the following specific conditions and requirements, as applicable:
(1) Batteries —(i) Nonspillable wet electric storage batteries . Nonspillable wet electric storage batteries are not subject to the requirements of this subchapter provided—
(A) The battery meets the conditions specified in Special Provision 67 of the ICAO Technical Instructions;
(B) The battery, its outer packaging, and any overpack are plainly and durably marked “NONSPILLABLE” or “NONSPILLABLE BATTERY”; and
© The batteries or battery assemblies are offered for transportation or transported in a manner that prevents short circuiting or forced discharge, including, but not limited to, protection of exposed terminals.