"Considering the seriousness of the charge I am surprised that the judge granted him unconditional bail."
Although there are some extra considerations where the defendant is charged with murder, the seriousness of the charge is not among the criteria when deciding whether bail should be granted or not. The Bail Act says that there is a general right to bail unless "...the court is satisfied that there are substantial grounds for believing that the defendant, if released on bail (whether subject to conditions or not) would—
(a) Fail to surrender to custody, or
(b) Commit an offence while on bail, or
(c) Iinterfere with witnesses or otherwise obstruct the course of justice, whether in relation to himself or any other person.
Before the decision to refuse bail is made the court must be satisfied that one of the risks above the risk exists and that no bail conditions are appropriate to obviate the risk. Note that the court must have "substantial grounds" for believing that one of the risks are present and not simply a hunch. In the case of absconding the court must have evidence that (say) he has failed to answer bail in the past and that failure is likely to be repeated.