is JodaModule thread safe or not?

Question

we had this weird bug that when we read data out of MySQL database and deserialize it to POJO,

Cannot parse \"2014-02-29T00:00:00+0000\": Value 29 for dayOfMonth must be in the range [1,28] (through reference chain: com.reports.common.SearchResult[\"entities\"]->java.util.HashSet[19]->com.reports.common.User[\"registrationDate\"])"}

as we checked the records in database, there is no records show registrationDate as '2014-02-29', the closest thing is '2014-02-19'. we use multi-threads to read data out of Mysql table, I'm wondering if it's because the Joda's dateTime deserializer is thread unsafe?

and here is our POJO:

public class SearchResult {
    @JsonProperty("entities")
    Set<User> users = new HashSet<>();
    String totalRecords;
}

public class User {
    private String email;
    private String gui;
    private DateTime creationDate;
    private DateTime registrationDate;
}

and here is our ObjectMapper:

public class PyObjectMapper extends ObjectMapper {
    public PyObjectMapper() {
        registerModule(new JodaModule());
    }
}

in our code we use multi-threads to call client code who read from database and map the result to POJO

result = client.getResourceLocator().getMembers(orgId, query,returnFields, bookmark, limit);

            if (result != null) {
                try {
                    searchResult = mapper.readValue(result.toString(), SearchResult.class);
                } catch (Exception e) {
                    throw e;
                }

the joda we used in pom are:

<dependency>
  <groupId>joda-time</groupId>
  <artifactId>joda-time</artifactId>
  <version>2.2</version>
</dependency>
<dependency>
  <groupId>com.fasterxml.jackson.datatype</groupId>
  <artifactId>jackson-datatype-joda</artifactId>
  <version>2.6.6</version>
</dependency>