bf's boss called him at 1AM

okay so my boyfriend is new to his job and his workmates are just his age, including the boss (22-23 years old).

they all went out for dinner and he got home at around 12am. when we were chatting, he told me to wait because his boss was calling. at 1 freakin' AM, asking if he already got home.

(his boss is a girl)

should i be worried?