MVC3 custom unobtrusive validation - force validation from checkbox

I have the following class used for custom validation:

[AttributeUsage(AttributeTargets.Property, AllowMultiple=false, Inherited=true)]
public sealed class RequiredIfAnyTrueAttribute : ValidationAttribute, IClientValidatable
{
    private const string DefaultErrorMessage = "{0} is required";

    public List<string> OtherProperties { get; private set; }

    public RequiredIfAnyTrueAttribute(string otherProperties)
        : base(DefaultErrorMessage)
    {
        if (string.IsNullOrEmpty(otherProperties))
            throw new ArgumentNullException("otherProperty");

        OtherProperties = new List<string>(otherProperties.Split(new char[] { '|', ',' }));
    }

    public override string FormatErrorMessage(string name)
    {
        return string.Format(ErrorMessageString, name);
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if (value == null)
        {
            foreach (string s in OtherProperties)
            {
                var otherProperty = validationContext.ObjectType.GetProperty(s);
                var otherPropertyValue = otherProperty.GetValue(validationContext.ObjectInstance, null);

                if (otherPropertyValue.Equals(true))
                    return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
            }
        }

        return ValidationResult.Success;
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var clientValidationRule = new ModelClientValidationRule()
        {
            ErrorMessage = FormatErrorMessage(metadata.GetDisplayName()),
            ValidationType = "requiredifanytrue"
        };

        clientValidationRule.ValidationParameters.Add("otherproperties", string.Join("|",OtherProperties));

        return new[] { clientValidationRule };
    }
}

My ViewModel is:

public class SampleViewModel
{
    public bool PropABC { get; set; }
    public bool PropXYZ { get; set; }

    [RequiredIfAnyTrue("PropABC|PropXYZ")]
    public int? TestField { get; set; }
}

When my strongly typed view renders, everything sees to work fine. If PropABC or PropXYZ is selected then I am required to enter a value for TestField. Both client and server-side validation is functional.

However, given the following sequence of events:

1. check PropABC
2. submit form
3. client-side validation fires for TestField required
4. uncheck PropABC
5. client validation does not re-fire and validation message remains until form submit

In order to resolve #5 I would typically attach click events to the checkboxes via jquery onready to refire the validation.

Is there a preferred/recommended way to manually force client-side validation given MVC3 + unobstrusive + jquery?